Imported from /home/lorry/working-area/delta_boost-tarball/boost_1_58_0.tar.bz2.HEADboost_1_58_0master

46 files changed, 6030 insertions, 75 deletions

diff --git a/libs/context/doc/acknowledgements.qbk b/libs/context/doc/acknowledgements.qbk
index 257b83dcf..df69bd5a4 100644
--- a/libs/context/doc/acknowledgements.qbk
+++ b/libs/context/doc/acknowledgements.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
diff --git a/libs/context/doc/architectures.qbk b/libs/context/doc/architectures.qbk
index 1eedc2499..b1ddd62d1 100644
--- a/libs/context/doc/architectures.qbk
+++ b/libs/context/doc/architectures.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
diff --git a/libs/context/doc/context.qbk b/libs/context/doc/context.qbk
index b576ed270..9b801e644 100644
--- a/libs/context/doc/context.qbk
+++ b/libs/context/doc/context.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
@@ -8,7 +8,7 @@
 [library Context
     [quickbook 1.5]
     [authors [Kowalke, Oliver]]
-    [copyright 2009 Oliver Kowalke]
+    [copyright 2014 Oliver Kowalke]
     [id context]
     [purpose C++ Library for swiching different user ctx]
     [category text]
@@ -22,8 +22,6 @@
 
 [def __boost_build__ [*Boost.Build]]
 [def __boost_context__ [*Boost.Context]]
-[def __boost_fiber__ [*Boost.Coroutine]]
-[def __boost_task__ [*Boost.Task]]
 
 [template cs_example_link[link_text] [link context.examples.enumerator [link_text]]]
 [template context_link[link_text] [link context.context.context [link_text]]]
@@ -42,9 +40,16 @@
 [def __threads__ ['threads]]
 [def __tls__ ['thread-local storage]]
 [def __stack_allocator__ ['StackAllocator]]
+[def __stack_allocator_concept__ ['stack-allocator concept]]
+[def __stack_traits__ ['stack-traits]]
 
+[def __econtext__ ['execution_context]]
 [def __fcontext__ ['fcontext_t]]
 [def __ucontext__ ['ucontext_t]]
+[def __fixedsize__ ['fixedsize_stack]]
+[def __protected_fixedsize__ ['protected_fixedsize_stack]]
+[def __segmented__ ['segmented_stack]]
+[def __stack_context__ ['stack_context]]
 
 [def __fls_alloc__ ['::FlsAlloc()]]
 [def __fls_free__ ['::FlsFree()]]
@@ -65,6 +70,8 @@
 [include overview.qbk]
 [include requirements.qbk]
 [include fcontext.qbk]
+[include execution_context.qbk]
+[include stack.qbk]
 [include performance.qbk]
 [include architectures.qbk]
 [include rationale.qbk]
diff --git a/libs/context/doc/context.xml b/libs/context/doc/context.xml
new file mode 100644
index 000000000..f77e2173c
--- /dev/null
+++ b/libs/context/doc/context.xml
@@ -0,0 +1,2283 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN" "http://www.boost.org/tools/boostbook/dtd/boostbook.dtd">
+<library id="context" name="Context" dirname="context" last-revision="$Date: 2015/03/05 16:26:31 $"
+ xmlns:xi="http://www.w3.org/2001/XInclude">
+  <libraryinfo>
+    <authorgroup>
+    <author>
+      <firstname>Oliver</firstname> <surname>Kowalke</surname>
+    </author>
+    </authorgroup>
+    <copyright>
+      <year>2014</year> <holder>Oliver Kowalke</holder>
+    </copyright>
+    <legalnotice id="context.legal">
+      <para>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <ulink url="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</ulink>)
+      </para>
+    </legalnotice>
+    <librarypurpose>
+      C++ Library for swiching different user ctx
+    </librarypurpose>
+    <librarycategory name="category:text"></librarycategory>
+  </libraryinfo>
+  <title>Context</title>
+  <section id="context.overview">
+    <title><link linkend="context.overview">Overview</link></title>
+    <para>
+      <emphasis role="bold">Boost.Context</emphasis> is a foundational library that
+      provides a sort of cooperative multitasking on a single thread. By providing
+      an abstraction of the current execution state in the current thread, including
+      the stack (with local variables) and stack pointer, all registers and CPU flags,
+      and the instruction pointer, a <emphasis>fcontext_t</emphasis> instance represents
+      a specific point in the application's execution path. This is useful for building
+      higher-level abstractions, like <emphasis>coroutines</emphasis>, <emphasis>cooperative
+      threads (userland threads)</emphasis> or an equivalent to <ulink url="http://msdn.microsoft.com/en-us/library/9k7k7cf0%28v=vs.80%29.aspx">C#
+      keyword <emphasis>yield</emphasis></ulink> in C++.
+    </para>
+    <para>
+      A <emphasis>fcontext_t</emphasis> provides the means to suspend the current
+      execution path and to transfer execution control, thereby permitting another
+      <emphasis>fcontext_t</emphasis> to run on the current thread. This state full
+      transfer mechanism enables a <emphasis>fcontext_t</emphasis> to suspend execution
+      from within nested functions and, later, to resume from where it was suspended.
+      While the execution path represented by a <emphasis>fcontext_t</emphasis> only
+      runs on a single thread, it can be migrated to another thread at any given
+      time.
+    </para>
+    <para>
+      A context switch between threads requires system calls (involving the OS kernel),
+      which can cost more than thousand CPU cycles on x86 CPUs. By contrast, transferring
+      control among them requires only few CPU cycles because it does not involve
+      system calls as it is done within a single thread.
+    </para>
+    <para>
+      In order to use the classes and functions described here, you can either include
+      the specific headers specified by the descriptions of each class or function,
+      or include the master library header:
+    </para>
+<programlisting><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">context</phrase><phrase role="special">/</phrase><phrase role="identifier">all</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+</programlisting>
+    <para>
+      which includes all the other headers in turn.
+    </para>
+    <para>
+      All functions and classes are contained in the namespace <emphasis>boost::context</emphasis>.
+    </para>
+  </section>
+  <section id="context.requirements">
+    <title><link linkend="context.requirements">Requirements</link></title>
+    <para>
+      <emphasis role="bold">Boost.Context</emphasis> must be built for the particular
+      compiler(s) and CPU architecture(s)s being targeted. <emphasis role="bold">Boost.Context</emphasis>
+      includes assembly code and, therefore, requires GNU as and GNU preprocesspr
+      for supported POSIX systems, MASM for Windows/x86 systems and ARMasm for Windows/arm
+      systems.
+    </para>
+    <note>
+      <para>
+        MASM64 (ml64.exe) is a part of Microsoft's Windows Driver Kit.
+      </para>
+    </note>
+    <important>
+      <para>
+        Please note that <code><phrase role="identifier">address</phrase><phrase
+        role="special">-</phrase><phrase role="identifier">model</phrase><phrase
+        role="special">=</phrase><phrase role="number">64</phrase></code> must be
+        given to bjam command line on 64bit Windows for 64bit build; otherwise 32bit
+        code will be generated.
+      </para>
+    </important>
+    <important>
+      <para>
+        For cross-compiling the lib you must specify certain additional properties
+        at bjam command line: <code><phrase role="identifier">target</phrase><phrase
+        role="special">-</phrase><phrase role="identifier">os</phrase></code>, <code><phrase
+        role="identifier">abi</phrase></code>, <code><phrase role="identifier">binary</phrase><phrase
+        role="special">-</phrase><phrase role="identifier">format</phrase></code>,
+        <code><phrase role="identifier">architecture</phrase></code> and <code><phrase
+        role="identifier">address</phrase><phrase role="special">-</phrase><phrase
+        role="identifier">model</phrase></code>.
+      </para>
+    </important>
+  </section>
+  <section id="context.context">
+    <title><link linkend="context.context">Struct fcontext_t</link></title>
+    <para>
+      Each instance of <emphasis>fcontext_t</emphasis> represents a context (CPU
+      registers and stack space). Together with its related functions <emphasis>jump_fcontext()</emphasis>
+      and <emphasis>make_fcontext()</emphasis> it provides a execution control transfer
+      mechanism similar interface like <ulink url="http://www.kernel.org/doc/man-pages/online/pages/man2/getcontext.2.html">ucontext_t</ulink>.
+      <emphasis>fcontext_t</emphasis> and its functions are located in <emphasis>boost::context</emphasis>
+      and the functions are declared as extern &quot;C&quot;.
+    </para>
+    <warning>
+      <para>
+        If <emphasis>fcontext_t</emphasis> is used in a multi threaded application,
+        it can migrated between threads, but must not reference <emphasis>thread-local
+        storage</emphasis>.
+      </para>
+    </warning>
+    <important>
+      <para>
+        The low level API is the part to port to new platforms.
+      </para>
+    </important>
+    <note>
+      <para>
+        If <emphasis>fiber-local storage</emphasis> is used on Windows, the user
+        is responsible for calling <emphasis>::FlsAlloc()</emphasis>, <emphasis>::FlsFree()</emphasis>.
+      </para>
+    </note>
+    <bridgehead renderas="sect3" id="context.context.h0">
+      <phrase id="context.context.executing_a_context"/><link linkend="context.context.executing_a_context">Executing
+      a context</link>
+    </bridgehead>
+    <para>
+      A new context supposed to execute a <emphasis>context-function</emphasis> (returning
+      void and accepting intptr_t as argument) will be created on top of the stack
+      (at 16 byte boundary) by function <emphasis>make_fcontext()</emphasis>.
+    </para>
+<programlisting><phrase role="comment">// context-function</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">intptr</phrase><phrase role="special">);</phrase>
+
+<phrase role="comment">// creates a new stack</phrase>
+<phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase> <phrase role="special">=</phrase> <phrase role="number">8192</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">void</phrase><phrase role="special">*</phrase> <phrase role="identifier">sp</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">malloc</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">));</phrase>
+
+<phrase role="comment">// context fc uses f() as context function</phrase>
+<phrase role="comment">// fcontext_t is placed on top of context stack</phrase>
+<phrase role="comment">// a pointer to fcontext_t is returned</phrase>
+<phrase role="identifier">fcontext_t</phrase> <phrase role="identifier">fc</phrase><phrase role="special">(</phrase><phrase role="identifier">make_fcontext</phrase><phrase role="special">(</phrase><phrase role="identifier">sp</phrase><phrase role="special">,</phrase><phrase role="identifier">size</phrase><phrase role="special">,</phrase><phrase role="identifier">f</phrase><phrase role="special">));</phrase>
+</programlisting>
+    <para>
+      Calling <emphasis>jump_fcontext()</emphasis> invokes the <emphasis>context-function</emphasis>
+      in a newly created context complete with registers, flags, stack and instruction
+      pointers. When control should be returned to the original calling context,
+      call <emphasis>jump_fcontext()</emphasis>. The current context information
+      (registers, flags, and stack and instruction pointers) is saved and the original
+      context information is restored. Calling <emphasis>jump_fcontext()</emphasis>
+      again resumes execution in the second context after saving the new state of
+      the original context.
+    </para>
+<programlisting><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">fcontext_t</phrase> <phrase role="identifier">fcm</phrase><phrase role="special">,</phrase><phrase role="identifier">fc1</phrase><phrase role="special">,</phrase><phrase role="identifier">fc2</phrase><phrase role="special">;</phrase>
+
+<phrase role="keyword">void</phrase> <phrase role="identifier">f1</phrase><phrase role="special">(</phrase><phrase role="identifier">intptr_t</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot;f1: entered&quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot;f1: call jump_fcontext( &amp; fc1, fc2, 0)&quot;</phrase><phrase role="special">&lt;&lt;</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fc1</phrase><phrase role="special">,</phrase><phrase role="identifier">fc2</phrase><phrase role="special">,</phrase><phrase role="number">0</phrase><phrase role="special">);</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot;f1: return&quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fc1</phrase><phrase role="special">,</phrase><phrase role="identifier">fcm</phrase><phrase role="special">,</phrase><phrase role="number">0</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">void</phrase> <phrase role="identifier">f2</phrase><phrase role="special">(</phrase><phrase role="identifier">intptr_t</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot;f2: entered&quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot;f2: call jump_fcontext( &amp; fc2, fc1, 0)&quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fc2</phrase><phrase role="special">,</phrase><phrase role="identifier">fc1</phrase><phrase role="special">,</phrase><phrase role="number">0</phrase><phrase role="special">);</phrase>
+    <phrase role="identifier">BOOST_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">&amp;&amp;!</phrase><phrase role="string">&quot;f2: never returns&quot;</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase role="special">(</phrase><phrase role="number">8192</phrase><phrase role="special">);</phrase>
+<phrase role="keyword">void</phrase><phrase role="special">*</phrase> <phrase role="identifier">sp1</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">malloc</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">));</phrase>
+<phrase role="keyword">void</phrase><phrase role="special">*</phrase> <phrase role="identifier">sp2</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">malloc</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">));</phrase>
+
+<phrase role="identifier">fc1</phrase><phrase role="special">=</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">make_fcontext</phrase><phrase role="special">(</phrase><phrase role="identifier">sp1</phrase><phrase role="special">,</phrase><phrase role="identifier">size</phrase><phrase role="special">,</phrase><phrase role="identifier">f1</phrase><phrase role="special">);</phrase>
+<phrase role="identifier">fc2</phrase><phrase role="special">=</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">make_fcontext</phrase><phrase role="special">(</phrase><phrase role="identifier">sp2</phrase><phrase role="special">,</phrase><phrase role="identifier">size</phrase><phrase role="special">,</phrase><phrase role="identifier">f2</phrase><phrase role="special">);</phrase>
+
+<phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot;main: call jump_fcontext( &amp; fcm, fc1, 0)&quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fcm</phrase><phrase role="special">,</phrase><phrase role="identifier">fc1</phrase><phrase role="special">,</phrase><phrase role="number">0</phrase><phrase role="special">);</phrase>
+
+<phrase role="identifier">output</phrase><phrase role="special">:</phrase>
+    <phrase role="identifier">main</phrase><phrase role="special">:</phrase> <phrase role="identifier">call</phrase> <phrase role="identifier">jump_fcontext</phrase><phrase role="special">(</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">fcm</phrase><phrase role="special">,</phrase> <phrase role="identifier">fc1</phrase><phrase role="special">,</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
+    <phrase role="identifier">f1</phrase><phrase role="special">:</phrase> <phrase role="identifier">entered</phrase>
+    <phrase role="identifier">f1</phrase><phrase role="special">:</phrase> <phrase role="identifier">call</phrase> <phrase role="identifier">jump_fcontext</phrase><phrase role="special">(</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">fc1</phrase><phrase role="special">,</phrase> <phrase role="identifier">fc2</phrase><phrase role="special">,</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
+    <phrase role="identifier">f2</phrase><phrase role="special">:</phrase> <phrase role="identifier">entered</phrase>
+    <phrase role="identifier">f2</phrase><phrase role="special">:</phrase> <phrase role="identifier">call</phrase> <phrase role="identifier">jump_fcontext</phrase><phrase role="special">(</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">fc2</phrase><phrase role="special">,</phrase> <phrase role="identifier">fc1</phrase><phrase role="special">,</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
+    <phrase role="identifier">f1</phrase><phrase role="special">:</phrase> <phrase role="keyword">return</phrase>
+</programlisting>
+    <para>
+      First call of <emphasis>jump_fcontext()</emphasis> enters the <emphasis>context-function</emphasis>
+      <code><phrase role="identifier">f1</phrase><phrase role="special">()</phrase></code>
+      by starting context fc1 (context fcm saves the registers of <code><phrase role="identifier">main</phrase><phrase
+      role="special">()</phrase></code>). For jumping between context's fc1 and fc2
+      <code><phrase role="identifier">jump_fcontext</phrase><phrase role="special">()</phrase></code>
+      is called. Because context fcm is chained to fc1, <code><phrase role="identifier">main</phrase><phrase
+      role="special">()</phrase></code> is entered (returning from <emphasis>jump_fcontext()</emphasis>)
+      after context fc1 becomes complete (return from <code><phrase role="identifier">f1</phrase><phrase
+      role="special">()</phrase></code>).
+    </para>
+    <warning>
+      <para>
+        Calling <emphasis>jump_fcontext()</emphasis> to the same context from inside
+        the same context results in undefined behaviour.
+      </para>
+    </warning>
+    <important>
+      <para>
+        The size of the stack is required to be larger than the size of fcontext_t.
+      </para>
+    </important>
+    <note>
+      <para>
+        In contrast to threads, which are preemtive, <emphasis>fcontext_t</emphasis>
+        switches are cooperative (programmer controls when switch will happen). The
+        kernel is not involved in the context switches.
+      </para>
+    </note>
+    <bridgehead renderas="sect3" id="context.context.h1">
+      <phrase id="context.context.transfer_of_data"/><link linkend="context.context.transfer_of_data">Transfer
+      of data</link>
+    </bridgehead>
+    <para>
+      The third argument passed to <emphasis>jump_fcontext()</emphasis>, in one context,
+      is passed as the first argument of the <emphasis>context-function</emphasis>
+      if the context is started for the first time. In all following invocations
+      of <emphasis>jump_fcontext()</emphasis> the intptr_t passed to <emphasis>jump_fcontext()</emphasis>,
+      in one context, is returned by <emphasis>jump_fcontext()</emphasis> in the
+      other context.
+    </para>
+<programlisting><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">fcontext_t</phrase> <phrase role="identifier">fcm</phrase><phrase role="special">,</phrase><phrase role="identifier">fc</phrase><phrase role="special">;</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">pair_t</phrase><phrase role="special">;</phrase>
+
+<phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">intptr_t</phrase> <phrase role="identifier">param</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="identifier">pair_t</phrase><phrase role="special">*</phrase> <phrase role="identifier">p</phrase><phrase role="special">=(</phrase><phrase role="identifier">pair_t</phrase><phrase role="special">*)</phrase><phrase role="identifier">param</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">p</phrase><phrase role="special">=(</phrase><phrase role="identifier">pair_t</phrase><phrase role="special">*)</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fc</phrase><phrase role="special">,</phrase><phrase role="identifier">fcm</phrase><phrase role="special">,(</phrase><phrase role="identifier">intptr_t</phrase><phrase role="special">)(</phrase><phrase role="identifier">p</phrase><phrase role="special">-&gt;</phrase><phrase role="identifier">first</phrase><phrase role="special">+</phrase><phrase role="identifier">p</phrase><phrase role="special">-&gt;</phrase><phrase role="identifier">second</phrase><phrase role="special">));</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fc</phrase><phrase role="special">,</phrase><phrase role="identifier">fcm</phrase><phrase role="special">,(</phrase><phrase role="identifier">intptr_t</phrase><phrase role="special">)(</phrase><phrase role="identifier">p</phrase><phrase role="special">-&gt;</phrase><phrase role="identifier">first</phrase><phrase role="special">+</phrase><phrase role="identifier">p</phrase><phrase role="special">-&gt;</phrase><phrase role="identifier">second</phrase><phrase role="special">));</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase role="special">(</phrase><phrase role="number">8192</phrase><phrase role="special">);</phrase>
+<phrase role="keyword">void</phrase><phrase role="special">*</phrase> <phrase role="identifier">sp</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">malloc</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">));</phrase>
+
+<phrase role="identifier">pair_t</phrase> <phrase role="identifier">p</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">make_pair</phrase><phrase role="special">(</phrase><phrase role="number">2</phrase><phrase role="special">,</phrase><phrase role="number">7</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">fc</phrase><phrase role="special">=</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">make_fcontext</phrase><phrase role="special">(</phrase><phrase role="identifier">sp</phrase><phrase role="special">,</phrase><phrase role="identifier">size</phrase><phrase role="special">,</phrase><phrase role="identifier">f</phrase><phrase role="special">);</phrase>
+
+<phrase role="keyword">int</phrase> <phrase role="identifier">res</phrase><phrase role="special">=(</phrase><phrase role="keyword">int</phrase><phrase role="special">)</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fcm</phrase><phrase role="special">,</phrase><phrase role="identifier">fc</phrase><phrase role="special">,(</phrase><phrase role="identifier">intptr_t</phrase><phrase role="special">)&amp;</phrase><phrase role="identifier">p</phrase><phrase role="special">);</phrase>
+<phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">p</phrase><phrase role="special">.</phrase><phrase role="identifier">first</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot; + &quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">p</phrase><phrase role="special">.</phrase><phrase role="identifier">second</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot; == &quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">res</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">p</phrase><phrase role="special">=</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">make_pair</phrase><phrase role="special">(</phrase><phrase role="number">5</phrase><phrase role="special">,</phrase><phrase role="number">6</phrase><phrase role="special">);</phrase>
+<phrase role="identifier">res</phrase><phrase role="special">=(</phrase><phrase role="keyword">int</phrase><phrase role="special">)</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">jump_fcontext</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">fcm</phrase><phrase role="special">,</phrase><phrase role="identifier">fc</phrase><phrase role="special">,(</phrase><phrase role="identifier">intptr_t</phrase><phrase role="special">)&amp;</phrase><phrase role="identifier">p</phrase><phrase role="special">);</phrase>
+<phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">p</phrase><phrase role="special">.</phrase><phrase role="identifier">first</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot; + &quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">p</phrase><phrase role="special">.</phrase><phrase role="identifier">second</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="string">&quot; == &quot;</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">res</phrase><phrase role="special">&lt;&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">output</phrase><phrase role="special">:</phrase>
+    <phrase role="number">2</phrase> <phrase role="special">+</phrase> <phrase role="number">7</phrase> <phrase role="special">==</phrase> <phrase role="number">9</phrase>
+    <phrase role="number">5</phrase> <phrase role="special">+</phrase> <phrase role="number">6</phrase> <phrase role="special">==</phrase> <phrase role="number">11</phrase>
+</programlisting>
+    <bridgehead renderas="sect3" id="context.context.h2">
+      <phrase id="context.context.exceptions_in__emphasis_context_function__emphasis_"/><link
+      linkend="context.context.exceptions_in__emphasis_context_function__emphasis_">Exceptions
+      in <emphasis>context-function</emphasis></link>
+    </bridgehead>
+    <para>
+      If the <emphasis>context-function</emphasis> emits an exception, the behaviour
+      is undefined.
+    </para>
+    <important>
+      <para>
+        <emphasis>context-function</emphasis> should wrap the code in a try/catch
+        block.
+      </para>
+    </important>
+    <important>
+      <para>
+        Do not jump from inside a catch block and than re-throw the exception in
+        another execution context.
+      </para>
+    </important>
+    <bridgehead renderas="sect3" id="context.context.h3">
+      <phrase id="context.context.preserving_floating_point_registers"/><link linkend="context.context.preserving_floating_point_registers">Preserving
+      floating point registers</link>
+    </bridgehead>
+    <para>
+      Preserving the floating point registers increases the cycle count for a context
+      switch (see performance tests). The fourth argument of <emphasis>jump_fcontext()</emphasis>
+      controls if fpu registers should be preserved by the context jump.
+    </para>
+    <important>
+      <para>
+        The use of the fpu controlling argument of <emphasis>jump_fcontext()</emphasis>
+        must be consistent in the application. Otherwise the behaviour is undefined.
+      </para>
+    </important>
+    <bridgehead renderas="sect3" id="context.context.h4">
+      <phrase id="context.context.stack_unwinding"/><link linkend="context.context.stack_unwinding">Stack
+      unwinding</link>
+    </bridgehead>
+    <para>
+      Sometimes it is necessary to unwind the stack of an unfinished context to destroy
+      local stack variables so they can release allocated resources (RAII pattern).
+      The user is responsible for this task.
+    </para>
+    <bridgehead renderas="sect3" id="context.context.h5">
+      <phrase id="context.context._code__phrase_role__identifier__fcontext_t__phrase___code__and_related_functions"/><link
+      linkend="context.context._code__phrase_role__identifier__fcontext_t__phrase___code__and_related_functions"><code><phrase
+      role="identifier">fcontext_t</phrase></code> and related functions</link>
+    </bridgehead>
+<programlisting><phrase role="keyword">struct</phrase> <phrase role="identifier">stack_t</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="keyword">void</phrase><phrase role="special">*</phrase> <phrase role="identifier">sp</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">opaque</phrase> <phrase role="identifier">pointer</phrase> <phrase role="special">&gt;</phrase> <phrase role="identifier">fcontext_t</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">intptr_t</phrase> <phrase role="identifier">jump_fcontext</phrase><phrase role="special">(</phrase><phrase role="identifier">fcontext_t</phrase><phrase role="special">*</phrase> <phrase role="identifier">ofc</phrase><phrase role="special">,</phrase><phrase role="identifier">fcontext_t</phrase> <phrase role="identifier">nfc</phrase><phrase role="special">,</phrase><phrase role="identifier">intptr_t</phrase> <phrase role="identifier">vp</phrase><phrase role="special">,</phrase><phrase role="keyword">bool</phrase> <phrase role="identifier">preserve_fpu</phrase><phrase role="special">=</phrase><phrase role="keyword">true</phrase><phrase role="special">);</phrase>
+<phrase role="identifier">fcontext_t</phrase> <phrase role="identifier">make_fcontext</phrase><phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">*</phrase> <phrase role="identifier">sp</phrase><phrase role="special">,</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase role="special">,</phrase><phrase role="keyword">void</phrase><phrase role="special">(*</phrase><phrase role="identifier">fn</phrase><phrase role="special">)(</phrase><phrase role="identifier">intptr_t</phrase><phrase role="special">));</phrase>
+</programlisting>
+    <bridgehead renderas="sect3" id="context.context.h6">
+      <phrase id="context.context._code__phrase_role__identifier__sp__phrase___code_"/><link
+      linkend="context.context._code__phrase_role__identifier__sp__phrase___code_"><code><phrase
+      role="identifier">sp</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Member:</term>
+        <listitem>
+          <para>
+            Pointer to the beginning of the stack (depending of the architecture
+            the stack grows downwards or upwards).
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.context.h7">
+      <phrase id="context.context._code__phrase_role__identifier__size__phrase___code_"/><link
+      linkend="context.context._code__phrase_role__identifier__size__phrase___code_"><code><phrase
+      role="identifier">size</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Member:</term>
+        <listitem>
+          <para>
+            Size of the stack in bytes.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.context.h8">
+      <phrase id="context.context._code__phrase_role__identifier__fc_stack__phrase___code_"/><link
+      linkend="context.context._code__phrase_role__identifier__fc_stack__phrase___code_"><code><phrase
+      role="identifier">fc_stack</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Member:</term>
+        <listitem>
+          <para>
+            Tracks the memory for the context's stack.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.context.h9">
+      <phrase id="context.context._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"/><link
+      linkend="context.context._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"><code><phrase
+      role="identifier">intptr_t</phrase> <phrase role="identifier">jump_fcontext</phrase><phrase
+      role="special">(</phrase><phrase role="identifier">fcontext_t</phrase><phrase
+      role="special">*</phrase> <phrase role="identifier">ofc</phrase><phrase role="special">,</phrase><phrase
+      role="identifier">fcontext_t</phrase> <phrase role="identifier">nfc</phrase><phrase
+      role="special">,</phrase><phrase role="identifier">intptr_t</phrase> <phrase
+      role="identifier">p</phrase><phrase role="special">,</phrase><phrase role="keyword">bool</phrase>
+      <phrase role="identifier">preserve_fpu</phrase><phrase role="special">=</phrase><phrase
+      role="keyword">true</phrase><phrase role="special">)</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Stores the current context data (stack pointer, instruction pointer,
+            and CPU registers) to <code><phrase role="special">*</phrase><phrase
+            role="identifier">ofc</phrase></code> and restores the context data from
+            <code><phrase role="identifier">nfc</phrase></code>, which implies jumping
+            to <code><phrase role="identifier">nfc</phrase></code>'s execution context.
+            The intptr_t argument, <code><phrase role="identifier">p</phrase></code>,
+            is passed to the current context to be returned by the most recent call
+            to <code><phrase role="identifier">jump_fcontext</phrase><phrase role="special">()</phrase></code>
+            in the same thread. The last argument controls if fpu registers have
+            to be preserved.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Returns:</term>
+        <listitem>
+          <para>
+            The third pointer argument passed to the most recent call to <code><phrase
+            role="identifier">jump_fcontext</phrase><phrase role="special">()</phrase></code>,
+            if any.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.context.h10">
+      <phrase id="context.context._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"/><link
+      linkend="context.context._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"><code><phrase
+      role="identifier">fcontext_t</phrase> <phrase role="identifier">make_fcontext</phrase><phrase
+      role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">*</phrase>
+      <phrase role="identifier">sp</phrase><phrase role="special">,</phrase><phrase
+      role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase>
+      <phrase role="identifier">size</phrase><phrase role="special">,</phrase><phrase
+      role="keyword">void</phrase><phrase role="special">(*</phrase><phrase role="identifier">fn</phrase><phrase
+      role="special">)(</phrase><phrase role="identifier">intptr_t</phrase><phrase
+      role="special">))</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Precondition:</term>
+        <listitem>
+          <para>
+            Stack <code><phrase role="identifier">sp</phrase></code> and function
+            pointer <code><phrase role="identifier">fn</phrase></code> are valid
+            (depending on the architecture <code><phrase role="identifier">sp</phrase></code>
+            points to the top or bottom of the stack) and <code><phrase role="identifier">size</phrase></code>
+            &gt; 0.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Creates an fcontext_t on top of the stack and prepares the stack to execute
+            the <emphasis>context-function</emphasis> <code><phrase role="identifier">fn</phrase></code>.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Returns:</term>
+        <listitem>
+          <para>
+            Returns a fcontext_t which is placed on the stack.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </section>
+  <section id="context.econtext">
+    <title><link linkend="context.econtext">Class execution_context</link></title>
+    <important>
+      <para>
+        <emphasis>execution_context</emphasis> is supported only by C++14.
+      </para>
+    </important>
+    <para>
+      Class <emphasis>execution_context</emphasis> encapsulates <emphasis>fcontext_t</emphasis>
+      and related functions ( <emphasis>jump_fcontext()</emphasis> and <emphasis>make_fcontext()</emphasis>)
+      as well as stack management. <emphasis>execution_context</emphasis> permits
+      access to the current, active context via <code><phrase role="identifier">execution_context</phrase><phrase
+      role="special">::</phrase><phrase role="identifier">current</phrase><phrase
+      role="special">()</phrase></code>.
+    </para>
+<programlisting><phrase role="comment">/*
+ * grammar:
+ *   P ---&gt; E '\0'
+ *   E ---&gt; T {('+'|'-') T}
+ *   T ---&gt; S {('*'|'/') S}
+ *   S ---&gt; digit | '(' E ')'
+ */</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">Parser</phrase><phrase role="special">{</phrase>
+    <phrase role="comment">// implementation omitted; see examples directory</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">istringstream</phrase> <phrase role="identifier">is</phrase><phrase role="special">(</phrase><phrase role="string">&quot;1+1&quot;</phrase><phrase role="special">);</phrase>
+    <phrase role="keyword">bool</phrase> <phrase role="identifier">done</phrase><phrase role="special">=</phrase><phrase role="keyword">false</phrase><phrase role="special">;</phrase>
+    <phrase role="keyword">char</phrase> <phrase role="identifier">c</phrase><phrase role="special">;</phrase>
+
+    <phrase role="comment">// create handle to main execution context</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">execution_context</phrase> <phrase role="identifier">main_ctx</phrase><phrase role="special">(</phrase>
+        <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">execution_context</phrase><phrase role="special">::</phrase><phrase role="identifier">current</phrase><phrase role="special">()</phrase> <phrase role="special">);</phrase>
+
+    <phrase role="comment">// executes parser in new execution context</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">execution_context</phrase> <phrase role="identifier">parser_ctx</phrase><phrase role="special">(</phrase>
+        <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">fixedsize_stack</phrase><phrase role="special">(),</phrase>
+        <phrase role="special">[&amp;</phrase><phrase role="identifier">main_ctx</phrase><phrase role="special">,&amp;</phrase><phrase role="identifier">is</phrase><phrase role="special">,&amp;</phrase><phrase role="identifier">c</phrase><phrase role="special">,&amp;</phrase><phrase role="identifier">done</phrase><phrase role="special">](){</phrase>
+            <phrase role="comment">// create parser with callback function</phrase>
+            <phrase role="identifier">Parser</phrase> <phrase role="identifier">p</phrase><phrase role="special">(</phrase><phrase role="identifier">is</phrase><phrase role="special">,</phrase>
+                     <phrase role="special">[&amp;</phrase><phrase role="identifier">main_ctx</phrase><phrase role="special">,&amp;</phrase><phrase role="identifier">c</phrase><phrase role="special">](</phrase><phrase role="keyword">char</phrase> <phrase role="identifier">ch</phrase><phrase role="special">){</phrase>
+                         <phrase role="identifier">c</phrase><phrase role="special">=</phrase><phrase role="identifier">ch</phrase><phrase role="special">;</phrase>
+                         <phrase role="comment">// resume main execution context</phrase>
+                         <phrase role="identifier">main_ctx</phrase><phrase role="special">.</phrase><phrase role="identifier">resume</phrase><phrase role="special">();</phrase>
+                     <phrase role="special">});</phrase>
+            <phrase role="comment">// start recursive parsing</phrase>
+            <phrase role="identifier">p</phrase><phrase role="special">.</phrase><phrase role="identifier">run</phrase><phrase role="special">();</phrase>
+            <phrase role="identifier">done</phrase><phrase role="special">=</phrase><phrase role="keyword">true</phrase><phrase role="special">;</phrase>
+            <phrase role="comment">// return to main execution context</phrase>
+            <phrase role="identifier">main_ctx</phrase><phrase role="special">.</phrase><phrase role="identifier">resume</phrase><phrase role="special">();</phrase>
+        <phrase role="special">});</phrase>
+
+    <phrase role="comment">// user-code pulls parsed data from parser</phrase>
+    <phrase role="comment">// inverted control flow</phrase>
+    <phrase role="identifier">parser_ctx</phrase><phrase role="special">.</phrase><phrase role="identifier">resume</phrase><phrase role="special">();</phrase>
+    <phrase role="keyword">do</phrase> <phrase role="special">{</phrase>
+        <phrase role="identifier">printf</phrase><phrase role="special">(</phrase><phrase role="string">&quot;Parsed: %c\n&quot;</phrase><phrase role="special">,</phrase><phrase role="identifier">c</phrase><phrase role="special">);</phrase>
+        <phrase role="identifier">parser_ctx</phrase><phrase role="special">.</phrase><phrase role="identifier">resume</phrase><phrase role="special">();</phrase>
+    <phrase role="special">}</phrase> <phrase role="keyword">while</phrase><phrase role="special">(</phrase> <phrase role="special">!</phrase> <phrase role="identifier">done</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="identifier">output</phrase><phrase role="special">:</phrase>
+    <phrase role="identifier">Parsed</phrase><phrase role="special">:</phrase> <phrase role="number">1</phrase>
+    <phrase role="identifier">Parsed</phrase><phrase role="special">:</phrase> <phrase role="special">+</phrase>
+    <phrase role="identifier">Parsed</phrase><phrase role="special">:</phrase> <phrase role="number">1</phrase>
+</programlisting>
+    <para>
+      In this example a recursive descent parser uses a callback to emit a newly
+      passed symbol. Using <emphasis>execution_context</emphasis> the control flow
+      can be inverted, e.g. the user-code pulls parsed symbols from the parser -
+      instead to get pushed from the parser (via callback).
+    </para>
+    <para>
+      The interface of <emphasis>execution_context</emphasis> does not transfer data.
+      This is not required because usually sharing data's address (pointer/reference)
+      sufficient.
+    </para>
+    <para>
+      If the code executed by <emphasis>execution_context</emphasis> emits an exception,
+      <code><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase
+      role="identifier">terminate</phrase><phrase role="special">()</phrase></code>
+      will be called.
+    </para>
+    <important>
+      <para>
+        Do not jump from inside a catch block and than re-throw exceptions in another
+        execution context.
+      </para>
+    </important>
+    <para>
+      Sometimes it is necessary to unwind the stack of an unfinished context to destroy
+      local stack variables so they can release allocated resources (RAII pattern).
+      The user is responsible for this task.
+    </para>
+    <bridgehead renderas="sect3" id="context.econtext.h0">
+      <phrase id="context.econtext.allocating_control_strutures_on_top_of_stack"/><link
+      linkend="context.econtext.allocating_control_strutures_on_top_of_stack">allocating
+      control strutures on top of stack</link>
+    </bridgehead>
+    <para>
+      Allocating control structures on top of the stack requires to allocated the
+      <emphasis>stack_context</emphasis> and create the control structure with placement
+      new before <emphasis>execution_context</emphasis> is created.
+    </para>
+    <note>
+      <para>
+        The user is responsible for destructing the control structure at the top
+        of the stack.
+      </para>
+    </note>
+<programlisting><phrase role="comment">// stack-alloctor used for (de-)allocating stack</phrase>
+<phrase role="identifier">fixedsize_stack</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">(</phrase> <phrase role="number">4048</phrase><phrase role="special">);</phrase>
+<phrase role="comment">// allocate stack space</phrase>
+<phrase role="identifier">stack_context</phrase> <phrase role="identifier">sctx</phrase><phrase role="special">(</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">.</phrase><phrase role="identifier">allocate</phrase><phrase role="special">()</phrase> <phrase role="special">);</phrase>
+<phrase role="comment">// reserve space for control structure on top of the stack</phrase>
+<phrase role="keyword">void</phrase> <phrase role="special">*</phrase> <phrase role="identifier">sp</phrase> <phrase role="special">=</phrase> <phrase role="keyword">static_cast</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">char</phrase> <phrase role="special">*</phrase> <phrase role="special">&gt;(</phrase> <phrase role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase role="identifier">sp</phrase><phrase role="special">)</phrase> <phrase role="special">-</phrase> <phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase> <phrase role="identifier">my_control_structure</phrase><phrase role="special">);</phrase>
+<phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase> <phrase role="special">=</phrase> <phrase role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase> <phrase role="special">-</phrase> <phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase> <phrase role="identifier">my_control_structure</phrase><phrase role="special">);</phrase>
+<phrase role="comment">// placement new creates control structure on reserved space</phrase>
+<phrase role="identifier">my_control_structure</phrase> <phrase role="special">*</phrase> <phrase role="identifier">cs</phrase> <phrase role="special">=</phrase> <phrase role="keyword">new</phrase> <phrase role="special">(</phrase> <phrase role="identifier">sp</phrase><phrase role="special">)</phrase> <phrase role="identifier">my_control_structure</phrase><phrase role="special">(</phrase> <phrase role="identifier">sp</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">,</phrase> <phrase role="identifier">sctx</phrase><phrase role="special">,</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">);</phrase>
+<phrase role="special">...</phrase>
+<phrase role="comment">// destructing the control structure</phrase>
+<phrase role="identifier">cs</phrase><phrase role="special">-&gt;~</phrase><phrase role="identifier">my_control_structure</phrase><phrase role="special">();</phrase>
+<phrase role="special">...</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_control_structure</phrase>  <phrase role="special">{</phrase>
+    <phrase role="comment">// execution context</phrase>
+    <phrase role="identifier">execution_context</phrase> <phrase role="identifier">ectx</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">StackAllocator</phrase> <phrase role="special">&gt;</phrase>
+    <phrase role="identifier">my_control_structure</phrase><phrase role="special">(</phrase> <phrase role="keyword">void</phrase> <phrase role="special">*</phrase> <phrase role="identifier">sp</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase role="special">,</phrase> <phrase role="identifier">stack_context</phrase> <phrase role="identifier">sctx</phrase><phrase role="special">,</phrase> <phrase role="identifier">StackAllocator</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
+        <phrase role="comment">// create execution context</phrase>
+        <phrase role="identifier">ectx</phrase><phrase role="special">(</phrase> <phrase role="identifier">preallocated</phrase><phrase role="special">(</phrase> <phrase role="identifier">sp</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">,</phrase> <phrase role="identifier">sctx</phrase><phrase role="special">),</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">,</phrase> <phrase role="identifier">entry_func</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
+    <phrase role="special">}</phrase>
+    <phrase role="special">...</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+    <bridgehead renderas="sect3" id="context.econtext.h1">
+      <phrase id="context.econtext.exception_handling"/><link linkend="context.econtext.exception_handling">exception
+      handling</link>
+    </bridgehead>
+    <para>
+      If the function executed inside a <emphasis>execution_context</emphasis> emitts
+      ans exception, <code><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase
+      role="identifier">terminate</phrase><phrase role="special">()</phrase></code>
+      is called - <code><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase
+      role="identifier">exception_ptr</phrase></code> can used to store exceptions
+      thrown inside the other context.
+    </para>
+<programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">X</phrase> <phrase role="special">{</phrase>
+<phrase role="keyword">private</phrase><phrase role="special">:</phrase>
+    <phrase role="keyword">int</phrase> <phrase role="special">*</phrase> <phrase role="identifier">inp_</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">outp_</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">exception_ptr</phrase> <phrase role="identifier">excptr_</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">execution_context</phrase> <phrase role="identifier">caller_</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">execution_context</phrase> <phrase role="identifier">callee_</phrase><phrase role="special">;</phrase>
+
+<phrase role="keyword">public</phrase><phrase role="special">:</phrase>
+    <phrase role="identifier">X</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase>
+        <phrase role="identifier">inp_</phrase><phrase role="special">(</phrase> <phrase role="keyword">nullptr</phrase><phrase role="special">),</phrase>
+        <phrase role="identifier">outp_</phrase><phrase role="special">(),</phrase>
+        <phrase role="identifier">excptr_</phrase><phrase role="special">(),</phrase>
+        <phrase role="identifier">caller_</phrase><phrase role="special">(</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">execution_context</phrase><phrase role="special">::</phrase><phrase role="identifier">current</phrase><phrase role="special">()</phrase> <phrase role="special">),</phrase>
+        <phrase role="identifier">callee_</phrase><phrase role="special">(</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">context</phrase><phrase role="special">::</phrase><phrase role="identifier">fixedsize_stack</phrase><phrase role="special">(),</phrase>
+                 <phrase role="special">[=]</phrase> <phrase role="special">()</phrase> <phrase role="special">{</phrase>
+                    <phrase role="keyword">try</phrase> <phrase role="special">{</phrase>
+                        <phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase> <phrase role="identifier">inp_</phrase><phrase role="special">;</phrase>
+                        <phrase role="identifier">outp_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">lexical_cast</phrase><phrase role="special">&lt;</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="special">&gt;(</phrase> <phrase role="identifier">i</phrase><phrase role="special">);</phrase>
+                        <phrase role="identifier">caller_</phrase><phrase role="special">.</phrase><phrase role="identifier">resume</phrase><phrase role="special">();</phrase>
+                    <phrase role="special">}</phrase> <phrase role="keyword">catch</phrase> <phrase role="special">(...)</phrase> <phrase role="special">{</phrase>
+                        <phrase role="identifier">excptr_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">current_exception</phrase><phrase role="special">();</phrase>
+                    <phrase role="special">}</phrase>
+                 <phrase role="special">})</phrase>
+    <phrase role="special">{}</phrase>
+
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">operator</phrase><phrase role="special">()(</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
+        <phrase role="identifier">inp_</phrase> <phrase role="special">=</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">i</phrase><phrase role="special">;</phrase>
+        <phrase role="identifier">callee_</phrase><phrase role="special">.</phrase><phrase role="identifier">resume</phrase><phrase role="special">();</phrase>
+        <phrase role="keyword">if</phrase> <phrase role="special">(</phrase> <phrase role="identifier">excptr_</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
+            <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">rethrow_exception</phrase><phrase role="special">(</phrase> <phrase role="identifier">excptr_</phrase><phrase role="special">);</phrase>
+        <phrase role="special">}</phrase>
+        <phrase role="keyword">return</phrase> <phrase role="identifier">outp_</phrase><phrase role="special">;</phrase>
+    <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
+    <phrase role="identifier">X</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase> <phrase role="special">&lt;&lt;</phrase> <phrase role="identifier">x</phrase><phrase role="special">(</phrase> <phrase role="number">7</phrase><phrase role="special">)</phrase> <phrase role="special">&lt;&lt;</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase> <phrase role="special">&lt;&lt;</phrase> <phrase role="string">&quot;done&quot;</phrase> <phrase role="special">&lt;&lt;</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+    <bridgehead renderas="sect3" id="context.econtext.h2">
+      <phrase id="context.econtext.class__code__phrase_role__identifier__execution_context__phrase___code_"/><link
+      linkend="context.econtext.class__code__phrase_role__identifier__execution_context__phrase___code_">Class
+      <code><phrase role="identifier">execution_context</phrase></code></link>
+    </bridgehead>
+<programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">execution_context</phrase> <phrase role="special">{</phrase>
+<phrase role="keyword">public</phrase><phrase role="special">:</phrase>
+    <phrase role="keyword">static</phrase> <phrase role="identifier">execution_context</phrase> <phrase role="identifier">current</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&gt;</phrase>
+    <phrase role="identifier">execution_context</phrase><phrase role="special">(</phrase> <phrase role="identifier">StackAlloc</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">,</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="identifier">fn</phrase><phrase role="special">);</phrase>
+
+    <phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Fn</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="special">...</phrase> <phrase role="identifier">Args</phrase> <phrase role="special">&gt;</phrase>
+    <phrase role="identifier">execution_context</phrase><phrase role="special">(</phrase> <phrase role="identifier">StackAlloc</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">,</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="identifier">fn</phrase><phrase role="special">,</phrase> <phrase role="identifier">Args</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="special">...</phrase> <phrase role="identifier">args</phrase><phrase role="special">);</phrase>
+
+    <phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&gt;</phrase>
+    <phrase role="identifier">execution_context</phrase><phrase role="special">(</phrase> <phrase role="identifier">preallocated</phrase> <phrase role="identifier">palloc</phrase><phrase role="special">,</phrase> <phrase role="identifier">StackAlloc</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">,</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="identifier">fn</phrase><phrase role="special">);</phrase>
+
+    <phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Fn</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="special">...</phrase> <phrase role="identifier">Args</phrase> <phrase role="special">&gt;</phrase>
+    <phrase role="identifier">execution_context</phrase><phrase role="special">(</phrase> <phrase role="identifier">preallocated</phrase> <phrase role="identifier">palloc</phrase><phrase role="special">,</phrase> <phrase role="identifier">StackAlloc</phrase> <phrase role="identifier">salloc</phrase><phrase role="special">,</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="identifier">fn</phrase><phrase role="special">,</phrase> <phrase role="identifier">Args</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="special">...</phrase> <phrase role="identifier">args</phrase><phrase role="special">);</phrase>
+
+    <phrase role="keyword">void</phrase> <phrase role="identifier">resume</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">explicit</phrase> <phrase role="keyword">operator</phrase> <phrase role="keyword">bool</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">!()</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+    <bridgehead renderas="sect3" id="context.econtext.h3">
+      <phrase id="context.econtext._code__phrase_role__keyword__static__phrase___phrase_role__identifier__execution_context__phrase___phrase_role__identifier__current__phrase__phrase_role__special______phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__static__phrase___phrase_role__identifier__execution_context__phrase___phrase_role__identifier__current__phrase__phrase_role__special______phrase___code_"><code><phrase
+      role="keyword">static</phrase> <phrase role="identifier">execution_context</phrase>
+      <phrase role="identifier">current</phrase><phrase role="special">()</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Returns:</term>
+        <listitem>
+          <para>
+            Returns an instance of excution_context pointing to the active execution
+            context.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Throws:</term>
+        <listitem>
+          <para>
+            Nothing.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h4">
+      <phrase id="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"><code><phrase
+      role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase
+      role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">typname</phrase> <phrase
+      role="identifier">Fn</phrase> <phrase role="special">&gt;</phrase> <phrase
+      role="identifier">execution_context</phrase><phrase role="special">(</phrase>
+      <phrase role="identifier">StackAlloc</phrase> <phrase role="identifier">salloc</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase>
+      <phrase role="identifier">fn</phrase><phrase role="special">)</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Creates a new execution context and prepares the context to execute
+            <code><phrase role="identifier">fn</phrase></code>.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h5">
+      <phrase id="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"><code><phrase
+      role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase
+      role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">typname</phrase> <phrase
+      role="identifier">Fn</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase>
+      <phrase role="special">...</phrase> <phrase role="identifier">Args</phrase>
+      <phrase role="special">&gt;</phrase> <phrase role="identifier">execution_context</phrase><phrase
+      role="special">(</phrase> <phrase role="identifier">StackAlloc</phrase> <phrase
+      role="identifier">salloc</phrase><phrase role="special">,</phrase> <phrase
+      role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase
+      role="identifier">fn</phrase><phrase role="special">,</phrase> <phrase role="identifier">Args</phrase>
+      <phrase role="special">&amp;&amp;</phrase> <phrase role="special">...</phrase>
+      <phrase role="identifier">args</phrase><phrase role="special">)</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Creates a new execution context and prepares the context to execute
+            <code><phrase role="identifier">fn</phrase></code>.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h6">
+      <phrase id="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"><code><phrase
+      role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase
+      role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">typname</phrase> <phrase
+      role="identifier">Fn</phrase> <phrase role="special">&gt;</phrase> <phrase
+      role="identifier">execution_context</phrase><phrase role="special">(</phrase>
+      <phrase role="identifier">preallocated</phrase> <phrase role="identifier">palloc</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">StackAlloc</phrase> <phrase
+      role="identifier">salloc</phrase><phrase role="special">,</phrase> <phrase
+      role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase
+      role="identifier">fn</phrase><phrase role="special">)</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Creates a new execution context and prepares the context to execute
+            <code><phrase role="identifier">fn</phrase></code>. Used to store control
+            structures on top of the stack.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h7">
+      <phrase id="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"><code><phrase
+      role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase
+      role="keyword">typename</phrase> <phrase role="identifier">StackAlloc</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">typname</phrase> <phrase
+      role="identifier">Fn</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase>
+      <phrase role="special">...</phrase> <phrase role="identifier">Args</phrase>
+      <phrase role="special">&gt;</phrase> <phrase role="identifier">execution_context</phrase><phrase
+      role="special">(</phrase> <phrase role="identifier">preallocated</phrase>
+      <phrase role="identifier">palloc</phrase><phrase role="special">,</phrase>
+      <phrase role="identifier">StackAlloc</phrase> <phrase role="identifier">salloc</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">Fn</phrase> <phrase role="special">&amp;&amp;</phrase>
+      <phrase role="identifier">fn</phrase><phrase role="special">,</phrase> <phrase
+      role="identifier">Args</phrase> <phrase role="special">&amp;&amp;</phrase>
+      <phrase role="special">...</phrase> <phrase role="identifier">args</phrase><phrase
+      role="special">)</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Creates a new execution context and prepares the context to execute
+            <code><phrase role="identifier">fn</phrase></code>. Used to store control
+            structures on top of the stack.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h8">
+      <phrase id="context.econtext._code__phrase_role__keyword__void__phrase___phrase_role__identifier__resume__phrase__phrase_role__special______phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__void__phrase___phrase_role__identifier__resume__phrase__phrase_role__special______phrase___code_"><code><phrase
+      role="keyword">void</phrase> <phrase role="identifier">resume</phrase><phrase
+      role="special">()</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Stores internally the current context data (stack pointer, instruction
+            pointer, and CPU registers) to the current active context and restores
+            the context data from <code><phrase role="special">*</phrase><phrase
+            role="keyword">this</phrase></code>, which implies jumping to <code><phrase
+            role="special">*</phrase><phrase role="keyword">this</phrase></code>'s
+            execution context.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Note:</term>
+        <listitem>
+          <para>
+            The behaviour is undefined if <code><phrase role="identifier">resume</phrase><phrase
+            role="special">()</phrase></code> is called while <code><phrase role="identifier">execution_context</phrase><phrase
+            role="special">::</phrase><phrase role="identifier">current</phrase><phrase
+            role="special">()</phrase></code> returns <code><phrase role="special">*</phrase><phrase
+            role="keyword">this</phrase></code> (e.g. resuming an alredy running
+            cotnext).
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Throws:</term>
+        <listitem>
+          <para>
+            Nothing.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h9">
+      <phrase id="context.econtext._code__phrase_role__keyword__explicit__phrase___phrase_role__keyword__operator__phrase___phrase_role__keyword__bool__phrase__phrase_role__special______phrase___phrase_role__keyword__const__phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__explicit__phrase___phrase_role__keyword__operator__phrase___phrase_role__keyword__bool__phrase__phrase_role__special______phrase___phrase_role__keyword__const__phrase___code_"><code><phrase
+      role="keyword">explicit</phrase> <phrase role="keyword">operator</phrase>
+      <phrase role="keyword">bool</phrase><phrase role="special">()</phrase> <phrase
+      role="keyword">const</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Returns:</term>
+        <listitem>
+          <para>
+            If <code><phrase role="special">*</phrase><phrase role="keyword">this</phrase></code>
+            refers to an invalid context or the context-function has returned (completed),
+            the function returns <code><phrase role="keyword">false</phrase></code>.
+            Otherwise <code><phrase role="keyword">true</phrase></code>.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Throws:</term>
+        <listitem>
+          <para>
+            Nothing.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h10">
+      <phrase id="context.econtext._code__phrase_role__keyword__bool__phrase___phrase_role__keyword__operator__phrase__phrase_role__special_______phrase___phrase_role__keyword__const__phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__keyword__bool__phrase___phrase_role__keyword__operator__phrase__phrase_role__special_______phrase___phrase_role__keyword__const__phrase___code_"><code><phrase
+      role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase
+      role="special">!()</phrase> <phrase role="keyword">const</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Returns:</term>
+        <listitem>
+          <para>
+            If <code><phrase role="special">*</phrase><phrase role="keyword">this</phrase></code>
+            refers to an invalid context or the context-function has returned (completed),
+            the function returns <code><phrase role="keyword">true</phrase></code>.
+            Otherwise <code><phrase role="keyword">false</phrase></code>.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Throws:</term>
+        <listitem>
+          <para>
+            Nothing.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+    <bridgehead renderas="sect3" id="context.econtext.h11">
+      <phrase id="context.econtext.struct__code__phrase_role__identifier__preallocated__phrase___code_"/><link
+      linkend="context.econtext.struct__code__phrase_role__identifier__preallocated__phrase___code_">Struct
+      <code><phrase role="identifier">preallocated</phrase></code></link>
+    </bridgehead>
+<programlisting><phrase role="keyword">struct</phrase> <phrase role="identifier">preallocated</phrase> <phrase role="special">{</phrase>
+    <phrase role="keyword">void</phrase>        <phrase role="special">*</phrase>   <phrase role="identifier">sp</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase>     <phrase role="identifier">size</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">stack_context</phrase>   <phrase role="identifier">sctx</phrase><phrase role="special">;</phrase>
+
+    <phrase role="identifier">preallocated</phrase><phrase role="special">(</phrase> <phrase role="keyword">void</phrase> <phrase role="special">*</phrase> <phrase role="identifier">sp</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">:</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase role="special">,</phrase> <phrase role="identifier">stack_allocator</phrase> <phrase role="identifier">sctx</phrase><phrase role="special">)</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+    <bridgehead renderas="sect3" id="context.econtext.h12">
+      <phrase id="context.econtext._code__phrase_role__identifier__preallocated__phrase__phrase_role__special_____phrase___phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special_____phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_allocator__phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"/><link
+      linkend="context.econtext._code__phrase_role__identifier__preallocated__phrase__phrase_role__special_____phrase___phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special_____phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_allocator__phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code><phrase
+      role="identifier">preallocated</phrase><phrase role="special">(</phrase> <phrase
+      role="keyword">void</phrase> <phrase role="special">*</phrase> <phrase role="identifier">sp</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">:</phrase><phrase
+      role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase
+      role="special">,</phrase> <phrase role="identifier">stack_allocator</phrase>
+      <phrase role="identifier">sctx</phrase><phrase role="special">)</phrase></code></link>
+    </bridgehead>
+    <variablelist>
+      <title></title>
+      <varlistentry>
+        <term>Effects:</term>
+        <listitem>
+          <para>
+            Crreates an object of preallocated.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </section>
+  <section id="context.stack">
+    <title><link linkend="context.stack">Stack allocation</link></title>
+    <para>
+      The memory used by the stack is allocated/deallocated via a <emphasis>StackAllocator</emphasis>
+      which is required to model a <emphasis>stack-allocator concept</emphasis>.
+    </para>
+    <bridgehead renderas="sect3" id="context.stack.h0">
+      <phrase id="context.stack._emphasis_stack_allocator_concept__emphasis_"/><link
+      linkend="context.stack._emphasis_stack_allocator_concept__emphasis_"><emphasis>stack-allocator
+      concept</emphasis></link>
+    </bridgehead>
+    <para>
+      A <emphasis>StackAllocator</emphasis> must satisfy the <emphasis>stack-allocator
+      concept</emphasis> requirements shown in the following table, in which <code><phrase
+      role="identifier">a</phrase></code> is an object of a <emphasis>StackAllocator</emphasis>
+      type, <code><phrase role="identifier">sctx</phrase></code> is a <code><phrase
+      role="identifier">stack_context</phrase></code>, and <code><phrase role="identifier">size</phrase></code>
+      is a <code><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase
+      role="identifier">size_t</phrase></code>:
+    </para>
+    <informaltable frame="all">
+      <tgroup cols="3">
+        <thead>
+          <row>
+            <entry>
+              <para>
+                expression
+              </para>
+            </entry>
+            <entry>
+              <para>
+                return type
+              </para>
+            </entry>
+            <entry>
+              <para>
+                notes
+              </para>
+            </entry>
+          </row>
+        </thead>
+        <tbody>
+          <row>
+            <entry>
+              <para>
+                <code><phrase role="identifier">a</phrase><phrase role="special">(</phrase><phrase
+                role="identifier">size</phrase><phrase role="special">)</phrase></code>
+              </para>
+            </entry>
+            <entry>
+            </entry>
+            <entry>
+              <para>
+                creates a stack allocator
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                <code><phrase role="identifier">a</phrase><phrase role="special">.</phrase><phrase
+                role="identifier">allocate</phrase><phrase role="special">()</phrase></code>
+              </para>
+            </entry>
+            <entry>
+              <para>
+                <code><phrase role="identifier">stack_context</phrase></code>
+              </para>
+            </entry>
+            <entry>
+              <para>
+                creates a stack
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                <code><phrase role="identifier">a</phrase><phrase role="special">.</phrase><phrase
+                role="identifier">deallocate</phrase><phrase role="special">(</phrase>
+                <phrase role="identifier">sctx</phrase><phrase role="special">)</phrase></code>
+              </para>
+            </entry>
+            <entry>
+              <para>
+                <code><phrase role="keyword">void</phrase></code>
+              </para>
+            </entry>
+            <entry>
+              <para>
+                deallocates the stack created by <code><phrase role="identifier">a</phrase><phrase
+                role="special">.</phrase><phrase role="identifier">allocate</phrase><phrase
+                role="special">()</phrase></code>
+              </para>
+            </entry>
+          </row>
+        </tbody>
+      </tgroup>
+    </informaltable>
+    <important>
+      <para>
+        The implementation of <code><phrase role="identifier">allocate</phrase><phrase
+        role="special">()</phrase></code> might include logic to protect against
+        exceeding the context's available stack size rather than leaving it as undefined
+        behaviour.
+      </para>
+    </important>
+    <important>
+      <para>
+        Calling <code><phrase role="identifier">deallocate</phrase><phrase role="special">()</phrase></code>
+        with a <code><phrase role="identifier">stack_context</phrase></code> not
+        set by <code><phrase role="identifier">allocate</phrase><phrase role="special">()</phrase></code>
+        results in undefined behaviour.
+      </para>
+    </important>
+    <note>
+      <para>
+        The stack is not required to be aligned; alignment takes place inside <emphasis>execution_context</emphasis>.
+      </para>
+    </note>
+    <note>
+      <para>
+        Depending on the architecture <code><phrase role="identifier">allocate</phrase><phrase
+        role="special">()</phrase></code> stores an address from the top of the stack
+        (growing downwards) or the bottom of the stack (growing upwards).
+      </para>
+    </note>
+    <section id="context.stack.protected_fixedsize">
+      <title><link linkend="context.stack.protected_fixedsize">Class <emphasis>protected_fixedsize</emphasis></link></title>
+      <para>
+        <emphasis role="bold">Boost.Context</emphasis> provides the class <emphasis>protected_fixedsize_stack</emphasis>
+        which models the <emphasis>stack-allocator concept</emphasis>. It appends
+        a guard page at the end of each stack to protect against exceeding the stack.
+        If the guard page is accessed (read or write operation) a segmentation fault/access
+        violation is generated by the operating system.
+      </para>
+      <important>
+        <para>
+          Using <emphasis>protected_fixedsize_stack</emphasis> is expensive. That
+          is, launching a new coroutine with a new stack is expensive; the allocated
+          stack is just as efficient to use as any other stack.
+        </para>
+      </important>
+      <note>
+        <para>
+          The appended <code><phrase role="identifier">guard</phrase> <phrase role="identifier">page</phrase></code>
+          is <emphasis role="bold">not</emphasis> mapped to physical memory, only
+          virtual addresses are used.
+        </para>
+      </note>
+<programlisting><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">context</phrase><phrase role="special">/</phrase><phrase role="identifier">protected_fixedsize</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">traitsT</phrase> <phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">basic_protected_fixedsize</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="keyword">typedef</phrase> <phrase role="identifier">traitT</phrase>  <phrase role="identifier">traits_type</phrase><phrase role="special">;</phrase>
+
+    <phrase role="identifier">basic_protected_fixesize</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase> <phrase role="special">=</phrase> <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase role="identifier">default_size</phrase><phrase role="special">());</phrase>
+
+    <phrase role="identifier">stack_context</phrase> <phrase role="identifier">allocate</phrase><phrase role="special">();</phrase>
+
+    <phrase role="keyword">void</phrase> <phrase role="identifier">deallocate</phrase><phrase role="special">(</phrase> <phrase role="identifier">stack_context</phrase> <phrase role="special">&amp;);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">basic_protected_fixedsize</phrase><phrase role="special">&lt;</phrase> <phrase role="identifier">stack_traits</phrase> <phrase role="special">&gt;</phrase> <phrase role="identifier">protected_fixedsize</phrase>
+</programlisting>
+      <bridgehead renderas="sect4" id="context.stack.protected_fixedsize.h0">
+        <phrase id="context.stack.protected_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.protected_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="identifier">stack_context</phrase> <phrase role="identifier">allocate</phrase><phrase
+        role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Preconditions:</term>
+          <listitem>
+            <para>
+              <code><phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">minimum</phrase><phrase role="special">:</phrase><phrase
+              role="identifier">size</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&lt;=</phrase> <phrase role="identifier">size</phrase></code>
+              and <code><phrase role="special">!</phrase> <phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">is_unbounded</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&amp;&amp;</phrase>
+              <phrase role="special">(</phrase> <phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">maximum</phrase><phrase
+              role="special">:</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&gt;=</phrase> <phrase
+              role="identifier">size</phrase><phrase role="special">)</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Effects:</term>
+          <listitem>
+            <para>
+              Allocates memory of at least <code><phrase role="identifier">size</phrase></code>
+              Bytes and stores a pointer to the stack and its actual size in <code><phrase
+              role="identifier">sctx</phrase></code>. Depending on the architecture
+              (the stack grows downwards/upwards) the stored address is the highest/lowest
+              address of the stack.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.protected_fixedsize.h1">
+        <phrase id="context.stack.protected_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"/><link
+        linkend="context.stack.protected_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code><phrase
+        role="keyword">void</phrase> <phrase role="identifier">deallocate</phrase><phrase
+        role="special">(</phrase> <phrase role="identifier">stack_context</phrase>
+        <phrase role="special">&amp;</phrase> <phrase role="identifier">sctx</phrase><phrase
+        role="special">)</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Preconditions:</term>
+          <listitem>
+            <para>
+              <code><phrase role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase
+              role="identifier">sp</phrase></code> is valid, <code><phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">minimum</phrase><phrase
+              role="special">:</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&lt;=</phrase> <phrase
+              role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase
+              role="identifier">size</phrase></code> and <code><phrase role="special">!</phrase>
+              <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">is_unbounded</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&amp;&amp;</phrase> <phrase role="special">(</phrase>
+              <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">maximum</phrase><phrase role="special">:</phrase><phrase
+              role="identifier">size</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&gt;=</phrase> <phrase role="identifier">sctx</phrase><phrase
+              role="special">.</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">)</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Effects:</term>
+          <listitem>
+            <para>
+              Deallocates the stack space.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+    </section>
+    <section id="context.stack.fixedsize">
+      <title><link linkend="context.stack.fixedsize">Class <emphasis>fixedsize_stack</emphasis></link></title>
+      <para>
+        <emphasis role="bold">Boost.Context</emphasis> provides the class <emphasis>fixedsize_stack</emphasis>
+        which models the <emphasis>stack-allocator concept</emphasis>. In contrast
+        to <emphasis>protected_fixedsize_stack</emphasis> it does not append a guard
+        page at the end of each stack. The memory is simply managed by <code><phrase
+        role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">malloc</phrase><phrase
+        role="special">()</phrase></code> and <code><phrase role="identifier">std</phrase><phrase
+        role="special">::</phrase><phrase role="identifier">free</phrase><phrase
+        role="special">()</phrase></code>.
+      </para>
+<programlisting><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">context</phrase><phrase role="special">/</phrase><phrase role="identifier">fixedsize_stack</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">traitsT</phrase> <phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">basic_fixedsize_stack</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="keyword">typedef</phrase> <phrase role="identifier">traitT</phrase>  <phrase role="identifier">traits_type</phrase><phrase role="special">;</phrase>
+
+    <phrase role="identifier">basic_fixesize_stack</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase> <phrase role="special">=</phrase> <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase role="identifier">default_size</phrase><phrase role="special">());</phrase>
+
+    <phrase role="identifier">stack_context</phrase> <phrase role="identifier">allocate</phrase><phrase role="special">();</phrase>
+
+    <phrase role="keyword">void</phrase> <phrase role="identifier">deallocate</phrase><phrase role="special">(</phrase> <phrase role="identifier">stack_context</phrase> <phrase role="special">&amp;);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">basic_fixedsize_stack</phrase><phrase role="special">&lt;</phrase> <phrase role="identifier">stack_traits</phrase> <phrase role="special">&gt;</phrase> <phrase role="identifier">fixedsize_stack</phrase><phrase role="special">;</phrase>
+</programlisting>
+      <bridgehead renderas="sect4" id="context.stack.fixedsize.h0">
+        <phrase id="context.stack.fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="identifier">stack_context</phrase> <phrase role="identifier">allocate</phrase><phrase
+        role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Preconditions:</term>
+          <listitem>
+            <para>
+              <code><phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">minimum</phrase><phrase role="special">:</phrase><phrase
+              role="identifier">size</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&lt;=</phrase> <phrase role="identifier">size</phrase></code>
+              and <code><phrase role="special">!</phrase> <phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">is_unbounded</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&amp;&amp;</phrase>
+              <phrase role="special">(</phrase> <phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">maximum</phrase><phrase
+              role="special">:</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&gt;=</phrase> <phrase
+              role="identifier">size</phrase><phrase role="special">)</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Effects:</term>
+          <listitem>
+            <para>
+              Allocates memory of at least <code><phrase role="identifier">size</phrase></code>
+              Bytes and stores a pointer to the stack and its actual size in <code><phrase
+              role="identifier">sctx</phrase></code>. Depending on the architecture
+              (the stack grows downwards/upwards) the stored address is the highest/lowest
+              address of the stack.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.fixedsize.h1">
+        <phrase id="context.stack.fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"/><link
+        linkend="context.stack.fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code><phrase
+        role="keyword">void</phrase> <phrase role="identifier">deallocate</phrase><phrase
+        role="special">(</phrase> <phrase role="identifier">stack_context</phrase>
+        <phrase role="special">&amp;</phrase> <phrase role="identifier">sctx</phrase><phrase
+        role="special">)</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Preconditions:</term>
+          <listitem>
+            <para>
+              <code><phrase role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase
+              role="identifier">sp</phrase></code> is valid, <code><phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">minimum</phrase><phrase
+              role="special">:</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&lt;=</phrase> <phrase
+              role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase
+              role="identifier">size</phrase></code> and <code><phrase role="special">!</phrase>
+              <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">is_unbounded</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&amp;&amp;</phrase> <phrase role="special">(</phrase>
+              <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">maximum</phrase><phrase role="special">:</phrase><phrase
+              role="identifier">size</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&gt;=</phrase> <phrase role="identifier">sctx</phrase><phrase
+              role="special">.</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">)</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Effects:</term>
+          <listitem>
+            <para>
+              Deallocates the stack space.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+    </section>
+    <section id="context.stack.segmented">
+      <title><link linkend="context.stack.segmented">Class <emphasis>segmented_stack</emphasis></link></title>
+      <para>
+        <emphasis role="bold">Boost.Context</emphasis> supports usage of a <emphasis>segmented_stack</emphasis>,
+        e. g. the size of the stack grows on demand. The coroutine is created with
+        a minimal stack size and will be increased as required. Class <emphasis>segmented_stack</emphasis>
+        models the <emphasis>stack-allocator concept</emphasis>. In contrast to
+        <emphasis>protected_fixedsize_stack</emphasis> and <emphasis>fixedsize_stack</emphasis>
+        it creates a stack which grows on demand.
+      </para>
+      <note>
+        <para>
+          Segmented stacks are currently only supported by <emphasis role="bold">gcc</emphasis>
+          from version <emphasis role="bold">4.7</emphasis> <emphasis role="bold">clang</emphasis>
+          from version <emphasis role="bold">3.4</emphasis> onwards. In order to
+          use a __segmented_stack__ <emphasis role="bold">Boost.Context</emphasis>
+          must be built with <emphasis role="bold">toolset=gcc segmented-stacks=on</emphasis>
+          at b2/bjam command-line. Applications must be compiled with compiler-flags
+          <emphasis role="bold">-fsplit-stack -DBOOST_USE_SEGMENTED_STACKS</emphasis>.
+        </para>
+      </note>
+<programlisting><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">context</phrase><phrase role="special">/</phrase><phrase role="identifier">segmented_stack</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">traitsT</phrase> <phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">basic_segmented_stack</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="keyword">typedef</phrase> <phrase role="identifier">traitT</phrase>  <phrase role="identifier">traits_type</phrase><phrase role="special">;</phrase>
+
+    <phrase role="identifier">basic_segmented_stack</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase> <phrase role="special">=</phrase> <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase role="identifier">default_size</phrase><phrase role="special">());</phrase>
+
+    <phrase role="identifier">stack_context</phrase> <phrase role="identifier">allocate</phrase><phrase role="special">();</phrase>
+
+    <phrase role="keyword">void</phrase> <phrase role="identifier">deallocate</phrase><phrase role="special">(</phrase> <phrase role="identifier">stack_context</phrase> <phrase role="special">&amp;);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">basic_segmented_stack</phrase><phrase role="special">&lt;</phrase> <phrase role="identifier">stack_traits</phrase> <phrase role="special">&gt;</phrase> <phrase role="identifier">segmented_stack</phrase><phrase role="special">;</phrase>
+</programlisting>
+      <bridgehead renderas="sect4" id="context.stack.segmented.h0">
+        <phrase id="context.stack.segmented._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.segmented._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="identifier">stack_context</phrase> <phrase role="identifier">allocate</phrase><phrase
+        role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Preconditions:</term>
+          <listitem>
+            <para>
+              <code><phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">minimum</phrase><phrase role="special">:</phrase><phrase
+              role="identifier">size</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&lt;=</phrase> <phrase role="identifier">size</phrase></code>
+              and <code><phrase role="special">!</phrase> <phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">is_unbounded</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&amp;&amp;</phrase>
+              <phrase role="special">(</phrase> <phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">maximum</phrase><phrase
+              role="special">:</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&gt;=</phrase> <phrase
+              role="identifier">size</phrase><phrase role="special">)</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Effects:</term>
+          <listitem>
+            <para>
+              Allocates memory of at least <code><phrase role="identifier">size</phrase></code>
+              Bytes and stores a pointer to the stack and its actual size in <code><phrase
+              role="identifier">sctx</phrase></code>. Depending on the architecture
+              (the stack grows downwards/upwards) the stored address is the highest/lowest
+              address of the stack.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.segmented.h1">
+        <phrase id="context.stack.segmented._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"/><link
+        linkend="context.stack.segmented._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code><phrase
+        role="keyword">void</phrase> <phrase role="identifier">deallocate</phrase><phrase
+        role="special">(</phrase> <phrase role="identifier">stack_context</phrase>
+        <phrase role="special">&amp;</phrase> <phrase role="identifier">sctx</phrase><phrase
+        role="special">)</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Preconditions:</term>
+          <listitem>
+            <para>
+              <code><phrase role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase
+              role="identifier">sp</phrase></code> is valid, <code><phrase role="identifier">traits_type</phrase><phrase
+              role="special">::</phrase><phrase role="identifier">minimum</phrase><phrase
+              role="special">:</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">()</phrase> <phrase role="special">&lt;=</phrase> <phrase
+              role="identifier">sctx</phrase><phrase role="special">.</phrase><phrase
+              role="identifier">size</phrase></code> and <code><phrase role="special">!</phrase>
+              <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">is_unbounded</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&amp;&amp;</phrase> <phrase role="special">(</phrase>
+              <phrase role="identifier">traits_type</phrase><phrase role="special">::</phrase><phrase
+              role="identifier">maximum</phrase><phrase role="special">:</phrase><phrase
+              role="identifier">size</phrase><phrase role="special">()</phrase>
+              <phrase role="special">&gt;=</phrase> <phrase role="identifier">sctx</phrase><phrase
+              role="special">.</phrase><phrase role="identifier">size</phrase><phrase
+              role="special">)</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Effects:</term>
+          <listitem>
+            <para>
+              Deallocates the stack space.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+    </section>
+    <section id="context.stack.stack_traits">
+      <title><link linkend="context.stack.stack_traits">Class <emphasis>stack_traits</emphasis></link></title>
+      <para>
+        <emphasis>stack_traits</emphasis> models a <emphasis>stack-traits</emphasis>
+        providing a way to access certain properites defined by the enironment. Stack
+        allocators use <emphasis>stack-traits</emphasis> to allocate stacks.
+      </para>
+<programlisting><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">context</phrase><phrase role="special">/</phrase><phrase role="identifier">stack_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">struct</phrase> <phrase role="identifier">stack_traits</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="keyword">static</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">is_unbounded</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">page_size</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">default_size</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">minimum_size</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+
+    <phrase role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">maximum_size</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+      <bridgehead renderas="sect4" id="context.stack.stack_traits.h0">
+        <phrase id="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__keyword__bool__phrase___phrase_role__identifier__is_unbounded__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__keyword__bool__phrase___phrase_role__identifier__is_unbounded__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="keyword">static</phrase> <phrase role="keyword">bool</phrase> <phrase
+        role="identifier">is_unbounded</phrase><phrase role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Returns:</term>
+          <listitem>
+            <para>
+              Returns <code><phrase role="keyword">true</phrase></code> if the environment
+              defines no limit for the size of a stack.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Throws:</term>
+          <listitem>
+            <para>
+              Nothing.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.stack_traits.h1">
+        <phrase id="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__page_size__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__page_size__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase
+        role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase
+        role="identifier">page_size</phrase><phrase role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Returns:</term>
+          <listitem>
+            <para>
+              Returns the page size in bytes.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Throws:</term>
+          <listitem>
+            <para>
+              Nothing.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.stack_traits.h2">
+        <phrase id="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__default_size__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__default_size__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase
+        role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase
+        role="identifier">default_size</phrase><phrase role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Returns:</term>
+          <listitem>
+            <para>
+              Returns a default stack size, which may be platform specific. If the
+              stack is unbounded then the present implementation returns the maximum
+              of <code><phrase role="number">64</phrase> <phrase role="identifier">kB</phrase></code>
+              and <code><phrase role="identifier">minimum_size</phrase><phrase role="special">()</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Throws:</term>
+          <listitem>
+            <para>
+              Nothing.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.stack_traits.h3">
+        <phrase id="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__minimum_size__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__minimum_size__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase
+        role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase
+        role="identifier">minimum_size</phrase><phrase role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Returns:</term>
+          <listitem>
+            <para>
+              Returns the minimum size in bytes of stack defined by the environment
+              (Win32 4kB/Win64 8kB, defined by rlimit on POSIX).
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Throws:</term>
+          <listitem>
+            <para>
+              Nothing.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.stack_traits.h4">
+        <phrase id="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__maximum_size__phrase__phrase_role__special______phrase___code_"/><link
+        linkend="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__maximum_size__phrase__phrase_role__special______phrase___code_"><code><phrase
+        role="keyword">static</phrase> <phrase role="identifier">std</phrase><phrase
+        role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase
+        role="identifier">maximum_size</phrase><phrase role="special">()</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Preconditions:</term>
+          <listitem>
+            <para>
+              <code><phrase role="identifier">is_unbounded</phrase><phrase role="special">()</phrase></code>
+              returns <code><phrase role="keyword">false</phrase></code>.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Returns:</term>
+          <listitem>
+            <para>
+              Returns the maximum size in bytes of stack defined by the environment.
+            </para>
+          </listitem>
+        </varlistentry>
+        <varlistentry>
+          <term>Throws:</term>
+          <listitem>
+            <para>
+              Nothing.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+    </section>
+    <section id="context.stack.stack_context">
+      <title><link linkend="context.stack.stack_context">Class <emphasis>stack_context</emphasis></link></title>
+      <para>
+        <emphasis role="bold">Boost.Context</emphasis> provides the class <emphasis>stack_context</emphasis>
+        which will contain the stack pointer and the size of the stack. In case of
+        a <emphasis>segmented_stack</emphasis>, <emphasis>stack_context</emphasis>
+        contains some extra control structures.
+      </para>
+<programlisting><phrase role="keyword">struct</phrase> <phrase role="identifier">stack_context</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="keyword">void</phrase>    <phrase role="special">*</phrase>   <phrase role="identifier">sp</phrase><phrase role="special">;</phrase>
+    <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">size</phrase><phrase role="special">;</phrase>
+
+    <phrase role="comment">// might contain additional control structures</phrase>
+    <phrase role="comment">// for segmented stacks</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+      <bridgehead renderas="sect4" id="context.stack.stack_context.h0">
+        <phrase id="context.stack.stack_context._code__phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase___code_"/><link
+        linkend="context.stack.stack_context._code__phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase___code_"><code><phrase
+        role="keyword">void</phrase> <phrase role="special">*</phrase> <phrase role="identifier">sp</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Value:</term>
+          <listitem>
+            <para>
+              Pointer to the beginning of the stack.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+      <bridgehead renderas="sect4" id="context.stack.stack_context.h1">
+        <phrase id="context.stack.stack_context._code__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase___code_"/><link
+        linkend="context.stack.stack_context._code__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase___code_"><code><phrase
+        role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase>
+        <phrase role="identifier">size</phrase></code></link>
+      </bridgehead>
+      <variablelist>
+        <title></title>
+        <varlistentry>
+          <term>Value:</term>
+          <listitem>
+            <para>
+              Actual size of the stack.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+    </section>
+    <section id="context.stack.valgrind">
+      <title><link linkend="context.stack.valgrind">Support for valgrind</link></title>
+      <para>
+        Running programs that switch stacks under valgrind causes problems. Property
+        (b2 command-line) <code><phrase role="identifier">valgrind</phrase><phrase
+        role="special">=</phrase><phrase role="identifier">on</phrase></code> let
+        valgrind treat the memory regions as stack space which suppresses the errors.
+      </para>
+    </section>
+  </section>
+  <section id="context.performance">
+    <title><link linkend="context.performance">Performance</link></title>
+    <para>
+      Performance of <emphasis role="bold">Boost.Context</emphasis> was measured
+      on the platforms shown in the following table. Performance measurements were
+      taken using <code><phrase role="identifier">rdtsc</phrase></code> and <code><phrase
+      role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">chrono</phrase><phrase
+      role="special">::</phrase><phrase role="identifier">high_resolution_clock</phrase></code>,
+      with overhead corrections, on x86 platforms. In each case, cache warm-up was
+      accounted for, and the one running thread was pinned to a single CPU. The code
+      was compiled using the build options, 'variant = release cxxflags = -DBOOST_DISABLE_ASSERTS'.
+    </para>
+    <table frame="all" id="context.performance.performance_of_context_switch">
+      <title>Performance of context switch</title>
+      <tgroup cols="4">
+        <thead>
+          <row>
+            <entry>
+              <para>
+                Platform
+              </para>
+            </entry>
+            <entry>
+              <para>
+                ucontext_t
+              </para>
+            </entry>
+            <entry>
+              <para>
+                fcontext_t
+              </para>
+            </entry>
+            <entry>
+              <para>
+                windows fibers
+              </para>
+            </entry>
+          </row>
+        </thead>
+        <tbody>
+          <row>
+            <entry>
+              <para>
+                i386 <footnote id="context.performance.f0">
+                <para>
+                  AMD Athlon 64 DualCore 4400+
+                </para>
+                </footnote>
+              </para>
+            </entry>
+            <entry>
+              <para>
+                708 ns / 754 cycles
+              </para>
+            </entry>
+            <entry>
+              <para>
+                37 ns / 37 cycles
+              </para>
+            </entry>
+            <entry>
+              <para>
+                ns / cycles
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                x86_64 <footnote id="context.performance.f1">
+                <para>
+                  Intel Core2 Q6700
+                </para>
+                </footnote>
+              </para>
+            </entry>
+            <entry>
+              <para>
+                547 ns / 1433 cycles
+              </para>
+            </entry>
+            <entry>
+              <para>
+                8 ns / 23 cycles
+              </para>
+            </entry>
+            <entry>
+              <para>
+                ns / cycles
+              </para>
+            </entry>
+          </row>
+        </tbody>
+      </tgroup>
+    </table>
+  </section>
+  <section id="context.architectures">
+    <title><link linkend="context.architectures">Architectures</link></title>
+    <para>
+      <emphasis role="bold">Boost.Context</emphasis> supports following architectures:
+    </para>
+    <table frame="all" id="context.architectures.supported_architectures___abi_binary_format__">
+      <title>Supported architectures (&lt;ABI|binary format&gt;)</title>
+      <tgroup cols="5">
+        <thead>
+          <row>
+            <entry>
+              <para>
+                Architecture
+              </para>
+            </entry>
+            <entry>
+              <para>
+                LINUX (UNIX)
+              </para>
+            </entry>
+            <entry>
+              <para>
+                Windows
+              </para>
+            </entry>
+            <entry>
+              <para>
+                MacOS X
+              </para>
+            </entry>
+            <entry>
+              <para>
+                iOS
+              </para>
+            </entry>
+          </row>
+        </thead>
+        <tbody>
+          <row>
+            <entry>
+              <para>
+                arm
+              </para>
+            </entry>
+            <entry>
+              <para>
+                AAPCS|ELF
+              </para>
+            </entry>
+            <entry>
+              <para>
+                AAPCS|PE
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                AAPCS|MACH-O
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                i386
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|ELF
+              </para>
+            </entry>
+            <entry>
+              <para>
+                MS|PE
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|MACH-O
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                mips1
+              </para>
+            </entry>
+            <entry>
+              <para>
+                O32|ELF
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                ppc32
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|ELF,XCOFF
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|MACH-O
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                ppc64
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|ELF,XCOFF
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|MACH-O
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                sparc
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+          </row>
+          <row>
+            <entry>
+              <para>
+                x86_64
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV,X32|ELF
+              </para>
+            </entry>
+            <entry>
+              <para>
+                MS|PE
+              </para>
+            </entry>
+            <entry>
+              <para>
+                SYSV|MACH-O
+              </para>
+            </entry>
+            <entry>
+              <para>
+                -
+              </para>
+            </entry>
+          </row>
+        </tbody>
+      </tgroup>
+    </table>
+  </section>
+  <section id="context.rationale">
+    <title><link linkend="context.rationale">Rationale</link></title>
+    <bridgehead renderas="sect3" id="context.rationale.h0">
+      <phrase id="context.rationale.no_inline_assembler"/><link linkend="context.rationale.no_inline_assembler">No
+      inline-assembler</link>
+    </bridgehead>
+    <para>
+      Some newer compiler (for instance MSVC 10 for x86_64 and itanium) do not support
+      inline assembler. <footnote id="context.rationale.f0">
+      <para>
+        <ulink url="http://msdn.microsoft.com/en-us/library/4ks26t93.aspx">MSDN article
+        'Inline Assembler'</ulink>
+      </para>
+      </footnote>. Inlined assembler generates code bloating which his not welcome
+      on embedded systems.
+    </para>
+    <bridgehead renderas="sect3" id="context.rationale.h1">
+      <phrase id="context.rationale.fcontext_t"/><link linkend="context.rationale.fcontext_t">fcontext_t</link>
+    </bridgehead>
+    <para>
+      <emphasis role="bold">Boost.Context</emphasis> provides the low level API fcontext_t
+      which is implemented in assembler to provide context swapping operations. fcontext_t
+      is the part to port to new platforms.
+    </para>
+    <note>
+      <para>
+        Context switches do not preserve the signal mask on UNIX systems.
+      </para>
+    </note>
+    <para>
+      <emphasis>fcontext_t</emphasis> is an opaque pointer.
+    </para>
+    <section id="context.rationale.other_apis_">
+      <title><link linkend="context.rationale.other_apis_">Other APIs </link></title>
+      <bridgehead renderas="sect4" id="context.rationale.other_apis_.h0">
+        <phrase id="context.rationale.other_apis_.setjmp___longjmp__"/><link linkend="context.rationale.other_apis_.setjmp___longjmp__">setjmp()/longjmp()</link>
+      </bridgehead>
+      <para>
+        C99 defines <code><phrase role="identifier">setjmp</phrase><phrase role="special">()</phrase></code>/<code><phrase
+        role="identifier">longjmp</phrase><phrase role="special">()</phrase></code>
+        to provide non-local jumps but it does not require that <emphasis>longjmp()</emphasis>
+        preserves the current stack frame. Therefore, jumping into a function which
+        was exited via a call to <emphasis>longjmp()</emphasis> is undefined <footnote
+        id="context.rationale.other_apis_.f0">
+        <para>
+          ISO/IEC 9899:1999, 2005, 7.13.2.1:2
+        </para>
+        </footnote>.
+      </para>
+      <bridgehead renderas="sect4" id="context.rationale.other_apis_.h1">
+        <phrase id="context.rationale.other_apis_.ucontext_t"/><link linkend="context.rationale.other_apis_.ucontext_t">ucontext_t</link>
+      </bridgehead>
+      <para>
+        Since POSIX.1-2003 <code><phrase role="identifier">ucontext_t</phrase></code>
+        is deprecated and was removed in POSIX.1-2008! The function signature of
+        <code><phrase role="identifier">makecontext</phrase><phrase role="special">()</phrase></code>
+        is:
+      </para>
+<programlisting><phrase role="keyword">void</phrase> <phrase role="identifier">makecontext</phrase><phrase role="special">(</phrase><phrase role="identifier">ucontext_t</phrase> <phrase role="special">*</phrase><phrase role="identifier">ucp</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase> <phrase role="special">(*</phrase><phrase role="identifier">func</phrase><phrase role="special">)(),</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">argc</phrase><phrase role="special">,</phrase> <phrase role="special">...);</phrase>
+</programlisting>
+      <para>
+        The third argument of <code><phrase role="identifier">makecontext</phrase><phrase
+        role="special">()</phrase></code> specifies the number of integer arguments
+        that follow which will require function pointer cast if <code><phrase role="identifier">func</phrase></code>
+        will accept those arguments which is undefined in C99 <footnote id="context.rationale.other_apis_.f1">
+        <para>
+          ISO/IEC 9899:1999, 2005, J.2
+        </para>
+        </footnote>.
+      </para>
+      <para>
+        The arguments in the var-arg list are required to be integers, passing pointers
+        in var-arg list is not guaranteed to work, especially it will fail for architectures
+        where pointers are larger than integers.
+      </para>
+      <para>
+        <code><phrase role="identifier">ucontext_t</phrase></code> preserves signal
+        mask between context switches which involves system calls consuming a lot
+        of CPU cycles (ucontext_t is slower by perfomance_link[factor 13x] relative
+        to <code><phrase role="identifier">fcontext_t</phrase></code>).
+      </para>
+      <bridgehead renderas="sect4" id="context.rationale.other_apis_.h2">
+        <phrase id="context.rationale.other_apis_.windows_fibers"/><link linkend="context.rationale.other_apis_.windows_fibers">Windows
+        fibers</link>
+      </bridgehead>
+      <para>
+        A drawback of Windows Fiber API is that <code><phrase role="identifier">CreateFiber</phrase><phrase
+        role="special">()</phrase></code> does not accept a pointer to user allocated
+        stack space preventing the reuse of stacks for other context instances. Because
+        the Windows Fiber API requires to call <code><phrase role="identifier">ConvertThreadToFiber</phrase><phrase
+        role="special">()</phrase></code> if <code><phrase role="identifier">SwitchFiber</phrase><phrase
+        role="special">()</phrase></code> is called for a thread which has not been
+        converted to a fiber. For the same reason <code><phrase role="identifier">ConvertFiberToThread</phrase><phrase
+        role="special">()</phrase></code> must be called after return from <code><phrase
+        role="identifier">SwitchFiber</phrase><phrase role="special">()</phrase></code>
+        if the thread was forced to be converted to a fiber before (which is inefficient).
+      </para>
+<programlisting><phrase role="keyword">if</phrase> <phrase role="special">(</phrase> <phrase role="special">!</phrase> <phrase role="identifier">is_a_fiber</phrase><phrase role="special">()</phrase> <phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+    <phrase role="identifier">ConvertThreadToFiber</phrase><phrase role="special">(</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
+    <phrase role="identifier">SwitchToFiber</phrase><phrase role="special">(</phrase> <phrase role="identifier">ctx</phrase><phrase role="special">);</phrase>
+    <phrase role="identifier">ConvertFiberToThread</phrase><phrase role="special">();</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+      <para>
+        If the condition <code><phrase role="identifier">_WIN32_WINNT</phrase> <phrase
+        role="special">&gt;=</phrase> <phrase role="identifier">_WIN32_WINNT_VISTA</phrase></code>
+        is met function <code><phrase role="identifier">IsThreadAFiber</phrase><phrase
+        role="special">()</phrase></code> is provided in order to detect if the current
+        thread was already converted. Unfortunately Windows XP + SP 2/3 defines
+        <code><phrase role="identifier">_WIN32_WINNT</phrase> <phrase role="special">&gt;=</phrase>
+        <phrase role="identifier">_WIN32_WINNT_VISTA</phrase></code> without providing
+        <code><phrase role="identifier">IsThreadAFiber</phrase><phrase role="special">()</phrase></code>.
+      </para>
+    </section>
+    <section id="context.rationale.x86_and_floating_point_env">
+      <title><link linkend="context.rationale.x86_and_floating_point_env">x86 and
+      floating-point env</link></title>
+      <bridgehead renderas="sect4" id="context.rationale.x86_and_floating_point_env.h0">
+        <phrase id="context.rationale.x86_and_floating_point_env.i386"/><link linkend="context.rationale.x86_and_floating_point_env.i386">i386</link>
+      </bridgehead>
+      <para>
+        &quot;The FpCsr and the MxCsr register must be saved and restored before
+        any call or return by any procedure that needs to modify them ...&quot;
+        <footnote id="context.rationale.x86_and_floating_point_env.f0">
+        <para>
+          'Calling Conventions', Agner Fog
+        </para>
+        </footnote>.
+      </para>
+      <bridgehead renderas="sect4" id="context.rationale.x86_and_floating_point_env.h1">
+        <phrase id="context.rationale.x86_and_floating_point_env.x86_64"/><link linkend="context.rationale.x86_and_floating_point_env.x86_64">x86_64</link>
+      </bridgehead>
+      <bridgehead renderas="sect4" id="context.rationale.x86_and_floating_point_env.h2">
+        <phrase id="context.rationale.x86_and_floating_point_env.windows"/><link
+        linkend="context.rationale.x86_and_floating_point_env.windows">Windows</link>
+      </bridgehead>
+      <para>
+        MxCsr - &quot;A callee that modifies any of the non-volatile fields within
+        MxCsr must restore them before returning to its caller. Furthermore, a caller
+        that has modified any of these fields must restore them to their standard
+        values before invoking a callee ...&quot; <footnote id="context.rationale.x86_and_floating_point_env.f1">
+        <para>
+          <ulink url="http://http://msdn.microsoft.com/en-us/library/yxty7t75.aspx">MSDN
+          article 'MxCsr'</ulink>
+        </para>
+        </footnote>.
+      </para>
+      <para>
+        FpCsr - &quot;A callee that modifies any of the fields within FpCsr must
+        restore them before returning to its caller. Furthermore, a caller that has
+        modified any of these fields must restore them to their standard values before
+        invoking a callee ...&quot; <footnote id="context.rationale.x86_and_floating_point_env.f2">
+        <para>
+          <ulink url="http://http://msdn.microsoft.com/en-us/library/ms235300.aspx">MSDN
+          article 'FpCsr'</ulink>
+        </para>
+        </footnote>.
+      </para>
+      <para>
+        &quot;The MMX and floating-point stack registers (MM0-MM7/ST0-ST7) are preserved
+        across context switches. There is no explicit calling convention for these
+        registers.&quot; <footnote id="context.rationale.x86_and_floating_point_env.f3">
+        <para>
+          <ulink url="http://msdn.microsoft.com/en-us/library/a32tsf7t%28VS.80%29.aspx">MSDN
+          article 'Legacy Floating-Point Support'</ulink>
+        </para>
+        </footnote>.
+      </para>
+      <para>
+        &quot;The 64-bit Microsoft compiler does not use ST(0)-ST(7)/MM0-MM7&quot;.
+        <footnote id="context.rationale.x86_and_floating_point_env.f4">
+        <para>
+          'Calling Conventions', Agner Fog
+        </para>
+        </footnote>.
+      </para>
+      <para>
+        &quot;XMM6-XMM15 must be preserved&quot; <footnote id="context.rationale.x86_and_floating_point_env.f5">
+        <para>
+          <ulink url="http://msdn.microsoft.com/en-us/library/9z1stfyw%28v=vs.100%29.aspx">MSDN
+          article 'Register Usage'</ulink>
+        </para>
+        </footnote>
+      </para>
+      <bridgehead renderas="sect4" id="context.rationale.x86_and_floating_point_env.h3">
+        <phrase id="context.rationale.x86_and_floating_point_env.sysv"/><link linkend="context.rationale.x86_and_floating_point_env.sysv">SysV</link>
+      </bridgehead>
+      <para>
+        &quot;The control bits of the MxCsr register are callee-saved (preserved
+        across calls), while the status bits are caller-saved (not preserved). The
+        x87 status word register is caller-saved, whereas the x87 control word (FpCsr)
+        is callee-saved.&quot; <footnote id="context.rationale.x86_and_floating_point_env.f6">
+        <para>
+          SysV ABI AMD64 Architecture Processor Supplement Draft Version 0.99.4,
+          3.2.1
+        </para>
+        </footnote>.
+      </para>
+    </section>
+  </section>
+  <section id="context.reference">
+    <title><link linkend="context.reference">Reference</link></title>
+    <bridgehead renderas="sect3" id="context.reference.h0">
+      <phrase id="context.reference.arm"/><link linkend="context.reference.arm">ARM</link>
+    </bridgehead>
+    <itemizedlist>
+      <listitem>
+        <simpara>
+          AAPCS ABI: Procedure Call Standard for the ARM Architecture
+        </simpara>
+      </listitem>
+      <listitem>
+        <simpara>
+          AAPCS/LINUX: ARM GNU/Linux Application Binary Interface Supplement
+        </simpara>
+      </listitem>
+    </itemizedlist>
+    <bridgehead renderas="sect3" id="context.reference.h1">
+      <phrase id="context.reference.mips"/><link linkend="context.reference.mips">MIPS</link>
+    </bridgehead>
+    <itemizedlist>
+      <listitem>
+        <simpara>
+          O32 ABI: SYSTEM V APPLICATION BINARY INTERFACE, MIPS RISC Processor Supplement
+        </simpara>
+      </listitem>
+    </itemizedlist>
+    <bridgehead renderas="sect3" id="context.reference.h2">
+      <phrase id="context.reference.powerpc32"/><link linkend="context.reference.powerpc32">PowerPC32</link>
+    </bridgehead>
+    <itemizedlist>
+      <listitem>
+        <simpara>
+          SYSV ABI: SYSTEM V APPLICATION BINARY INTERFACE PowerPC Processor Supplement
+        </simpara>
+      </listitem>
+    </itemizedlist>
+    <bridgehead renderas="sect3" id="context.reference.h3">
+      <phrase id="context.reference.powerpc64"/><link linkend="context.reference.powerpc64">PowerPC64</link>
+    </bridgehead>
+    <itemizedlist>
+      <listitem>
+        <simpara>
+          SYSV ABI: PowerPC User Instruction Set Architecture, Book I
+        </simpara>
+      </listitem>
+    </itemizedlist>
+    <bridgehead renderas="sect3" id="context.reference.h4">
+      <phrase id="context.reference.x86_32"/><link linkend="context.reference.x86_32">X86-32</link>
+    </bridgehead>
+    <itemizedlist>
+      <listitem>
+        <simpara>
+          SYSV ABI: SYSTEM V APPLICATION BINARY INTERFACE, Intel386TM Architecture
+          Processor Supplement
+        </simpara>
+      </listitem>
+      <listitem>
+        <simpara>
+          MS PE: <ulink url="http://msdn.microsoft.com/en-us/library/k2b2ssfy.aspx">Calling
+          Conventions</ulink>
+        </simpara>
+      </listitem>
+    </itemizedlist>
+    <bridgehead renderas="sect3" id="context.reference.h5">
+      <phrase id="context.reference.x86_64"/><link linkend="context.reference.x86_64">X86-64</link>
+    </bridgehead>
+    <itemizedlist>
+      <listitem>
+        <simpara>
+          SYSV ABI: System V Application Binary Interface, AMD64 Architecture Processor
+          Supplement
+        </simpara>
+      </listitem>
+      <listitem>
+        <simpara>
+          MS PE: <ulink url="http://msdn.microsoft.com/en-us/library/7kcdt6fy%28VS.80%29.aspx">x64
+          Software Conventions</ulink>
+        </simpara>
+      </listitem>
+    </itemizedlist>
+  </section>
+  <section id="context.acknowledgements">
+    <title><link linkend="context.acknowledgements">Acknowledgments</link></title>
+    <para>
+      I'd like to thank Adreas Fett, Artyom Beilis, Daniel Larimer, David Deakins,
+      Evgeny Shapovalov, Fernando Pelliccioni, Giovanni Piero Deretta, Gordon Woodhull,
+      Helge Bahmann, Holger Grund, Jeffrey Lee Hellrung (Jr.), Keith Jeffery, Martin
+      Husemann, Phil Endecott, Robert Stewart, Sergey Cheban, Steven Watanabe, Vicente
+      J. Botet Escriba, Wayne Piekarski.
+    </para>
+  </section>
+</library>
diff --git a/libs/context/doc/execution_context.qbk b/libs/context/doc/execution_context.qbk
new file mode 100644
index 000000000..81535f7aa
--- /dev/null
+++ b/libs/context/doc/execution_context.qbk
@@ -0,0 +1,268 @@
+[/
+          Copyright Oliver Kowalke 2014.
+ Distributed under the Boost Software License, Version 1.0.
+    (See accompanying file LICENSE_1_0.txt or copy at
+          http://www.boost.org/LICENSE_1_0.txt
+]
+
+[section:econtext Class execution_context]
+
+[important __econtext__ is supported only by C++14.]
+
+Class __econtext__ encapsulates __fcontext__ and related functions (
+__jump_fcontext__ and __make_fcontext__) as well as stack management.
+__econtext__ permits access to the current, active context via
+`execution_context::current()`.
+
+        /*
+         * grammar:
+         *   P ---> E '\0'
+         *   E ---> T {('+'|'-') T}
+         *   T ---> S {('*'|'/') S}
+         *   S ---> digit | '(' E ')'
+         */
+        class Parser{
+            // implementation omitted; see examples directory
+        };
+
+        int main() {
+            std::istringstream is("1+1");
+            bool done=false;
+            char c;
+
+            // create handle to main execution context
+            boost::context::execution_context main_ctx(
+                boost::context::execution_context::current() );
+
+            // executes parser in new execution context
+            boost::context::execution_context parser_ctx(
+                boost::context::fixedsize_stack(),
+                [&main_ctx,&is,&c,&done](){
+                    // create parser with callback function
+                    Parser p(is,
+                             [&main_ctx,&c](char ch){
+                                 c=ch;
+                                 // resume main execution context
+                                 main_ctx.resume();
+                             });
+                    // start recursive parsing
+                    p.run();
+                    done=true;
+                    // return to main execution context
+                    main_ctx.resume();
+                });
+
+            // user-code pulls parsed data from parser
+            // inverted control flow
+            parser_ctx.resume();
+            do {
+                printf("Parsed: %c\n",c);
+                parser_ctx.resume();
+            } while( ! done);
+        }
+
+        output:
+            Parsed: 1
+            Parsed: +
+            Parsed: 1
+
+
+In this example a recursive descent parser uses a callback to emit a newly passed
+symbol. Using __econtext__ the control flow can be inverted, e.g. the user-code
+pulls parsed symbols from the parser - instead to get pushed from the parser
+(via callback).
+
+The interface of __econtext__ does not transfer data. This is not required
+because usually sharing data's address (pointer/reference) sufficient.
+
+If the code executed by __econtext__ emits an exception, `std::terminate()` will
+be called.
+
+[important Do not jump from inside a catch block and than re-throw exceptions in
+another execution context.]
+
+Sometimes it is necessary to unwind the stack of an unfinished context to
+destroy local stack variables so they can release allocated resources (RAII
+pattern). The user is responsible for this task.
+
+[heading allocating control strutures on top of stack]
+Allocating control structures on top of the stack requires to allocated the
+__stack_context__ and create the control structure with placement new before
+__econtext__ is created.
+[note The user is responsible for destructing the control structure at the top
+of the stack.]
+
+        // stack-alloctor used for (de-)allocating stack
+        fixedsize_stack salloc( 4048);
+        // allocate stack space
+        stack_context sctx( salloc.allocate() );
+        // reserve space for control structure on top of the stack
+        void * sp = static_cast< char * >( sctx.sp) - sizeof( my_control_structure);
+        std::size_t size = sctx.size - sizeof( my_control_structure);
+        // placement new creates control structure on reserved space
+        my_control_structure * cs = new ( sp) my_control_structure( sp, size, sctx, salloc);
+        ...
+        // destructing the control structure
+        cs->~my_control_structure();
+        ...
+        struct my_control_structure  {
+            // execution context
+            execution_context ectx;
+
+            template< typename StackAllocator >
+            my_control_structure( void * sp, std::size_t size, stack_context sctx, StackAllocator salloc) :
+                // create execution context
+                ectx( preallocated( sp, size, sctx), salloc, entry_func) {
+            }
+            ...
+        };
+
+[heading exception handling]
+If the function executed inside a __econtext__ emitts ans exception, `std::terminate()` is
+called - `std::exception_ptr` can used to store exceptions thrown inside the other context.
+
+[heading parameter passing]
+Input and output parameters are transfered via a lambda capture list and references/pointers.
+
+        class X {
+        private:
+            int * inp_;
+            std::string outp_;
+            std::exception_ptr excptr_;
+            boost::context::execution_context caller_;
+            boost::context::execution_context callee_;
+
+        public:
+            X() :
+                inp_( nullptr),
+                outp_(),
+                excptr_(),
+                caller_( boost::context::execution_context::current() ),
+                callee_( boost::context::fixedsize_stack(),
+                         [=] () {
+                            try {
+                                int i = * inp_;
+                                outp_ = boost::lexical_cast< std::string >( i);
+                                caller_.resume();
+                            } catch (...) {
+                                excptr_ = std::current_exception();
+                            }
+                         })
+            {}
+
+            std::string operator()( int i) {
+                inp_ = & i;
+                callee_.resume();
+                if ( excptr_) {
+                    std::rethrow_exception( excptr_);
+                }
+                return outp_;
+            }
+        };
+
+        int main() {
+            X x;
+            std::cout << x( 7) << std::endl;
+            std::cout << "done" << std::endl;
+        }
+
+
+[heading Class `execution_context`]
+
+        class execution_context {
+        public:
+            static execution_context current() noexcept;
+
+            template< typename StackAlloc, typename Fn >
+            execution_context( StackAlloc salloc, Fn && fn);
+
+            template< typename StackAlloc, typename Fn, typename ... Args >
+            execution_context( StackAlloc salloc, Fn && fn, Args && ... args);
+
+            template< typename StackAlloc, typename Fn >
+            execution_context( preallocated palloc, StackAlloc salloc, Fn && fn);
+
+            template< typename StackAlloc, typename Fn, typename ... Args >
+            execution_context( preallocated palloc, StackAlloc salloc, Fn && fn, Args && ... args);
+
+            void resume() noexcept;
+
+            explicit operator bool() const noexcept;
+
+            bool operator!() const noexcept;
+        };
+
+[heading `static execution_context current()`]
+[variablelist
+[[Returns:] [Returns an instance of excution_context pointing to the active
+execution context.]]
+[[Throws:] [Nothing.]]
+]
+
+[heading `template< typename StackAlloc, typname Fn > execution_context( StackAlloc salloc, Fn && fn)`]
+[variablelist
+[[Effects:] [Creates a new execution context and prepares the context to execute
+`fn`.]]
+]
+
+[heading `template< typename StackAlloc, typname Fn, typename ... Args > execution_context( StackAlloc salloc, Fn && fn, Args && ... args)`]
+[variablelist
+[[Effects:] [Creates a new execution context and prepares the context to execute
+`fn`.]]
+]
+
+[heading `template< typename StackAlloc, typname Fn > execution_context( preallocated palloc, StackAlloc salloc, Fn && fn)`]
+[variablelist
+[[Effects:] [Creates a new execution context and prepares the context to execute
+`fn`. Used to store control structures on top of the stack.]]
+]
+
+[heading `template< typename StackAlloc, typname Fn, typename ... Args > execution_context( preallocated palloc, StackAlloc salloc, Fn && fn, Args && ... args)`]
+[variablelist
+[[Effects:] [Creates a new execution context and prepares the context to execute
+`fn`. Used to store control structures on top of the stack.]]
+]
+
+[heading `void resume()`]
+[variablelist
+[[Effects:] [Stores internally the current context data (stack pointer,
+instruction pointer, and CPU registers) to the current active context and
+restores the context data from `*this`, which implies jumping to `*this`'s
+execution context.]]
+[[Note:] [The behaviour is undefined if `resume()` is called while `execution_context::current()`
+returns `*this` (e.g. resuming an alredy running cotnext).]]
+[[Throws:] [Nothing.]]
+]
+
+[heading `explicit operator bool() const`]
+[variablelist
+[[Returns:] [If `*this` refers to an invalid context or the context-function
+has returned (completed), the function returns `false`. Otherwise `true`.]]
+[[Throws:] [Nothing.]]
+]
+
+[heading `bool operator!() const`]
+[variablelist
+[[Returns:] [If `*this` refers to an invalid context or the context-function
+has returned (completed), the function returns `true`. Otherwise `false`.]]
+[[Throws:] [Nothing.]]
+]
+
+
+[heading Struct `preallocated`]
+
+        struct preallocated {
+            void        *   sp;
+            std::size_t     size;
+            stack_context   sctx;
+
+            preallocated( void * sp, std:size_t size, stack_allocator sctx) noexcept;
+        };
+
+[heading `preallocated( void * sp, std:size_t size, stack_allocator sctx)`]
+[variablelist
+[[Effects:] [Crreates an object of preallocated.]]
+]
+
+
+[endsect]
diff --git a/libs/context/doc/fcontext.qbk b/libs/context/doc/fcontext.qbk
index fd09da486..5e1a720eb 100644
--- a/libs/context/doc/fcontext.qbk
+++ b/libs/context/doc/fcontext.qbk
@@ -1,11 +1,11 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
 ]
 
-[section:context Context]
+[section:context Struct fcontext_t]
 
 Each instance of __fcontext__ represents a context (CPU registers and stack
 space). Together with its related functions __jump_fcontext__ and
@@ -70,7 +70,6 @@ new state of the original context.
             BOOST_ASSERT(false&&!"f2: never returns");
         }
 
-        boost::context::guarded_stack_allocator alloc;
         std::size_t size(8192);
         void* sp1(std::malloc(size));
         void* sp2(std::malloc(size));
@@ -125,9 +124,8 @@ other context.
             boost::context::jump_fcontext(&fc,fcm,(intptr_t)(p->first+p->second));
         }
 
-        boost::context::guarded_stack_allocator alloc;
         std::size_t size(8192);
-        void* sp(size);
+        void* sp(std::malloc(size));
 
         pair_t p(std::make_pair(2,7));
         fc=boost::context::make_fcontext(sp,size,f);
@@ -171,7 +169,7 @@ destroy local stack variables so they can release allocated resources (RAII
 pattern). The user is responsible for this task.
 
 
-[section:boost_fcontext `fcontext_t` and related functions]
+[heading `fcontext_t` and related functions]
 
         struct stack_t
         {
@@ -222,5 +220,3 @@ to execute the __context_fn__ `fn`.]]
 ]
 
 [endsect]
-
-[endsect]
diff --git a/libs/context/doc/html/context/acknowledgements.html b/libs/context/doc/html/context/acknowledgements.html
index d66de0837..3bc4f758a 100644
--- a/libs/context/doc/html/context/acknowledgements.html
+++ b/libs/context/doc/html/context/acknowledgements.html
@@ -35,7 +35,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>
diff --git a/libs/context/doc/html/context/architectures.html b/libs/context/doc/html/context/architectures.html
index 0b126c80b..7712f11f2 100644
--- a/libs/context/doc/html/context/architectures.html
+++ b/libs/context/doc/html/context/architectures.html
@@ -263,7 +263,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>
diff --git a/libs/context/doc/html/context/context.html b/libs/context/doc/html/context/context.html
index f3c1f5721..f8f23b66c 100644
--- a/libs/context/doc/html/context/context.html
+++ b/libs/context/doc/html/context/context.html
@@ -1,13 +1,13 @@
 <html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
-<title>Context</title>
+<title>Struct fcontext_t</title>
 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
 <link rel="home" href="../index.html" title="Chapter&#160;1.&#160;Context">
 <link rel="up" href="../index.html" title="Chapter&#160;1.&#160;Context">
 <link rel="prev" href="requirements.html" title="Requirements">
-<link rel="next" href="context/boost_fcontext.html" title="fcontext_t and related functions">
+<link rel="next" href="econtext.html" title="Class execution_context">
 </head>
 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
 <table cellpadding="2" width="100%"><tr>
@@ -20,14 +20,12 @@
 </tr></table>
 <hr>
 <div class="spirit-nav">
-<a accesskey="p" href="requirements.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="context/boost_fcontext.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+<a accesskey="p" href="requirements.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="econtext.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
 </div>
 <div class="section">
 <div class="titlepage"><div><div><h2 class="title" style="clear: both">
-<a name="context.context"></a><a class="link" href="context.html" title="Context">Context</a>
+<a name="context.context"></a><a class="link" href="context.html" title="Struct fcontext_t">Struct fcontext_t</a>
 </h2></div></div></div>
-<div class="toc"><dl class="toc"><dt><span class="section"><a href="context/boost_fcontext.html"><code class="computeroutput"><span class="identifier">fcontext_t</span></code>
-      and related functions</a></span></dt></dl></div>
 <p>
       Each instance of <span class="emphasis"><em>fcontext_t</em></span> represents a context (CPU
       registers and stack space). Together with its related functions <span class="emphasis"><em>jump_fcontext()</em></span>
@@ -117,7 +115,6 @@
     <span class="identifier">BOOST_ASSERT</span><span class="special">(</span><span class="keyword">false</span><span class="special">&amp;&amp;!</span><span class="string">"f2: never returns"</span><span class="special">);</span>
 <span class="special">}</span>
 
-<span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">guarded_stack_allocator</span> <span class="identifier">alloc</span><span class="special">;</span>
 <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">(</span><span class="number">8192</span><span class="special">);</span>
 <span class="keyword">void</span><span class="special">*</span> <span class="identifier">sp1</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">malloc</span><span class="special">(</span><span class="identifier">size</span><span class="special">));</span>
 <span class="keyword">void</span><span class="special">*</span> <span class="identifier">sp2</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">malloc</span><span class="special">(</span><span class="identifier">size</span><span class="special">));</span>
@@ -198,9 +195,8 @@
     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">jump_fcontext</span><span class="special">(&amp;</span><span class="identifier">fc</span><span class="special">,</span><span class="identifier">fcm</span><span class="special">,(</span><span class="identifier">intptr_t</span><span class="special">)(</span><span class="identifier">p</span><span class="special">-&gt;</span><span class="identifier">first</span><span class="special">+</span><span class="identifier">p</span><span class="special">-&gt;</span><span class="identifier">second</span><span class="special">));</span>
 <span class="special">}</span>
 
-<span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">guarded_stack_allocator</span> <span class="identifier">alloc</span><span class="special">;</span>
 <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">(</span><span class="number">8192</span><span class="special">);</span>
-<span class="keyword">void</span><span class="special">*</span> <span class="identifier">sp</span><span class="special">(</span><span class="identifier">size</span><span class="special">);</span>
+<span class="keyword">void</span><span class="special">*</span> <span class="identifier">sp</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">malloc</span><span class="special">(</span><span class="identifier">size</span><span class="special">));</span>
 
 <span class="identifier">pair_t</span> <span class="identifier">p</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">make_pair</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="number">7</span><span class="special">));</span>
 <span class="identifier">fc</span><span class="special">=</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">make_fcontext</span><span class="special">(</span><span class="identifier">sp</span><span class="special">,</span><span class="identifier">size</span><span class="special">,</span><span class="identifier">f</span><span class="special">);</span>
@@ -275,10 +271,120 @@
       local stack variables so they can release allocated resources (RAII pattern).
       The user is responsible for this task.
     </p>
+<h4>
+<a name="context.context.h5"></a>
+      <span class="phrase"><a name="context.context._code__phrase_role__identifier__fcontext_t__phrase___code__and_related_functions"></a></span><a class="link" href="context.html#context.context._code__phrase_role__identifier__fcontext_t__phrase___code__and_related_functions"><code class="computeroutput"><span class="identifier">fcontext_t</span></code> and related functions</a>
+    </h4>
+<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">stack_t</span>
+<span class="special">{</span>
+    <span class="keyword">void</span><span class="special">*</span> <span class="identifier">sp</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">;</span>
+<span class="special">};</span>
+
+<span class="keyword">typedef</span> <span class="special">&lt;</span><span class="identifier">opaque</span> <span class="identifier">pointer</span> <span class="special">&gt;</span> <span class="identifier">fcontext_t</span><span class="special">;</span>
+
+<span class="identifier">intptr_t</span> <span class="identifier">jump_fcontext</span><span class="special">(</span><span class="identifier">fcontext_t</span><span class="special">*</span> <span class="identifier">ofc</span><span class="special">,</span><span class="identifier">fcontext_t</span> <span class="identifier">nfc</span><span class="special">,</span><span class="identifier">intptr_t</span> <span class="identifier">vp</span><span class="special">,</span><span class="keyword">bool</span> <span class="identifier">preserve_fpu</span><span class="special">=</span><span class="keyword">true</span><span class="special">);</span>
+<span class="identifier">fcontext_t</span> <span class="identifier">make_fcontext</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span> <span class="identifier">sp</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">,</span><span class="keyword">void</span><span class="special">(*</span><span class="identifier">fn</span><span class="special">)(</span><span class="identifier">intptr_t</span><span class="special">));</span>
+</pre>
+<h4>
+<a name="context.context.h6"></a>
+      <span class="phrase"><a name="context.context._code__phrase_role__identifier__sp__phrase___code_"></a></span><a class="link" href="context.html#context.context._code__phrase_role__identifier__sp__phrase___code_"><code class="computeroutput"><span class="identifier">sp</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Member:</span></dt>
+<dd><p>
+            Pointer to the beginning of the stack (depending of the architecture
+            the stack grows downwards or upwards).
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.context.h7"></a>
+      <span class="phrase"><a name="context.context._code__phrase_role__identifier__size__phrase___code_"></a></span><a class="link" href="context.html#context.context._code__phrase_role__identifier__size__phrase___code_"><code class="computeroutput"><span class="identifier">size</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Member:</span></dt>
+<dd><p>
+            Size of the stack in bytes.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.context.h8"></a>
+      <span class="phrase"><a name="context.context._code__phrase_role__identifier__fc_stack__phrase___code_"></a></span><a class="link" href="context.html#context.context._code__phrase_role__identifier__fc_stack__phrase___code_"><code class="computeroutput"><span class="identifier">fc_stack</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Member:</span></dt>
+<dd><p>
+            Tracks the memory for the context's stack.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.context.h9"></a>
+      <span class="phrase"><a name="context.context._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="context.html#context.context._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="identifier">intptr_t</span> <span class="identifier">jump_fcontext</span><span class="special">(</span><span class="identifier">fcontext_t</span><span class="special">*</span> <span class="identifier">ofc</span><span class="special">,</span><span class="identifier">fcontext_t</span> <span class="identifier">nfc</span><span class="special">,</span><span class="identifier">intptr_t</span> <span class="identifier">p</span><span class="special">,</span><span class="keyword">bool</span>
+      <span class="identifier">preserve_fpu</span><span class="special">=</span><span class="keyword">true</span><span class="special">)</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Stores the current context data (stack pointer, instruction pointer,
+            and CPU registers) to <code class="computeroutput"><span class="special">*</span><span class="identifier">ofc</span></code> and restores the context data from
+            <code class="computeroutput"><span class="identifier">nfc</span></code>, which implies jumping
+            to <code class="computeroutput"><span class="identifier">nfc</span></code>'s execution context.
+            The intptr_t argument, <code class="computeroutput"><span class="identifier">p</span></code>,
+            is passed to the current context to be returned by the most recent call
+            to <code class="computeroutput"><span class="identifier">jump_fcontext</span><span class="special">()</span></code>
+            in the same thread. The last argument controls if fpu registers have
+            to be preserved.
+          </p></dd>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+            The third pointer argument passed to the most recent call to <code class="computeroutput"><span class="identifier">jump_fcontext</span><span class="special">()</span></code>,
+            if any.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.context.h10"></a>
+      <span class="phrase"><a name="context.context._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="context.html#context.context._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">fcontext_t</span> <span class="identifier">make_fcontext</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span>
+      <span class="identifier">sp</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span>
+      <span class="identifier">size</span><span class="special">,</span><span class="keyword">void</span><span class="special">(*</span><span class="identifier">fn</span><span class="special">)(</span><span class="identifier">intptr_t</span><span class="special">))</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Precondition:</span></dt>
+<dd><p>
+            Stack <code class="computeroutput"><span class="identifier">sp</span></code> and function
+            pointer <code class="computeroutput"><span class="identifier">fn</span></code> are valid
+            (depending on the architecture <code class="computeroutput"><span class="identifier">sp</span></code>
+            points to the top or bottom of the stack) and <code class="computeroutput"><span class="identifier">size</span></code>
+            &gt; 0.
+          </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Creates an fcontext_t on top of the stack and prepares the stack to execute
+            the <span class="emphasis"><em>context-function</em></span> <code class="computeroutput"><span class="identifier">fn</span></code>.
+          </p></dd>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+            Returns a fcontext_t which is placed on the stack.
+          </p></dd>
+</dl>
+</div>
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>
@@ -286,7 +392,7 @@
 </tr></table>
 <hr>
 <div class="spirit-nav">
-<a accesskey="p" href="requirements.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="context/boost_fcontext.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+<a accesskey="p" href="requirements.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="econtext.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
 </div>
 </body>
 </html>
diff --git a/libs/context/doc/html/context/context/boost_fcontext.html b/libs/context/doc/html/context/context/boost_fcontext.html
index 961d842d8..8afc10db0 100644
--- a/libs/context/doc/html/context/context/boost_fcontext.html
+++ b/libs/context/doc/html/context/context/boost_fcontext.html
@@ -3,11 +3,11 @@
 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
 <title>fcontext_t and related functions</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
-<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
 <link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
-<link rel="up" href="../context.html" title="Context">
-<link rel="prev" href="../context.html" title="Context">
-<link rel="next" href="../performance.html" title="Performance">
+<link rel="up" href="../context.html" title="Struct fcontext_t">
+<link rel="prev" href="../context.html" title="Struct fcontext_t">
+<link rel="next" href="../econtext.html" title="Class execution_context">
 </head>
 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
 <table cellpadding="2" width="100%"><tr>
@@ -20,7 +20,7 @@
 </tr></table>
 <hr>
 <div class="spirit-nav">
-<a accesskey="p" href="../context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../context.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../performance.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+<a accesskey="p" href="../context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../context.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../econtext.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
 </div>
 <div class="section">
 <div class="titlepage"><div><div><h3 class="title">
@@ -40,11 +40,11 @@
 </pre>
 <h5>
 <a name="context.context.boost_fcontext.h0"></a>
-        <span class="phrase"><a name="context.context.boost_fcontext._code__phrase_role__identifier__sp__phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__sp__phrase___code_"><code class="computeroutput"><span class="identifier">sp</span></code></a>
+        <span><a name="context.context.boost_fcontext._code__phrase_role__identifier__sp__phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__sp__phrase___code_"><code class="computeroutput"><span class="identifier">sp</span></code></a>
       </h5>
 <div class="variablelist">
 <p class="title"><b></b></p>
-<dl class="variablelist">
+<dl>
 <dt><span class="term">Member:</span></dt>
 <dd><p>
               Pointer to the beginning of the stack (depending of the architecture
@@ -54,11 +54,11 @@
 </div>
 <h5>
 <a name="context.context.boost_fcontext.h1"></a>
-        <span class="phrase"><a name="context.context.boost_fcontext._code__phrase_role__identifier__size__phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__size__phrase___code_"><code class="computeroutput"><span class="identifier">size</span></code></a>
+        <span><a name="context.context.boost_fcontext._code__phrase_role__identifier__size__phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__size__phrase___code_"><code class="computeroutput"><span class="identifier">size</span></code></a>
       </h5>
 <div class="variablelist">
 <p class="title"><b></b></p>
-<dl class="variablelist">
+<dl>
 <dt><span class="term">Member:</span></dt>
 <dd><p>
               Size of the stack in bytes.
@@ -67,11 +67,11 @@
 </div>
 <h5>
 <a name="context.context.boost_fcontext.h2"></a>
-        <span class="phrase"><a name="context.context.boost_fcontext._code__phrase_role__identifier__fc_stack__phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__fc_stack__phrase___code_"><code class="computeroutput"><span class="identifier">fc_stack</span></code></a>
+        <span><a name="context.context.boost_fcontext._code__phrase_role__identifier__fc_stack__phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__fc_stack__phrase___code_"><code class="computeroutput"><span class="identifier">fc_stack</span></code></a>
       </h5>
 <div class="variablelist">
 <p class="title"><b></b></p>
-<dl class="variablelist">
+<dl>
 <dt><span class="term">Member:</span></dt>
 <dd><p>
               Tracks the memory for the context's stack.
@@ -80,12 +80,12 @@
 </div>
 <h5>
 <a name="context.context.boost_fcontext.h3"></a>
-        <span class="phrase"><a name="context.context.boost_fcontext._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="identifier">intptr_t</span> <span class="identifier">jump_fcontext</span><span class="special">(</span><span class="identifier">fcontext_t</span><span class="special">*</span> <span class="identifier">ofc</span><span class="special">,</span><span class="identifier">fcontext_t</span> <span class="identifier">nfc</span><span class="special">,</span><span class="identifier">intptr_t</span> <span class="identifier">p</span><span class="special">,</span><span class="keyword">bool</span>
+        <span><a name="context.context.boost_fcontext._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__jump_fcontext__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase__phrase_role__special_____phrase___phrase_role__identifier__ofc__phrase__phrase_role__special_____phrase__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__nfc__phrase__phrase_role__special_____phrase__phrase_role__identifier__intptr_t__phrase___phrase_role__identifier__p__phrase__phrase_role__special_____phrase__phrase_role__keyword__bool__phrase___phrase_role__identifier__preserve_fpu__phrase__phrase_role__special_____phrase__phrase_role__keyword__true__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="identifier">intptr_t</span> <span class="identifier">jump_fcontext</span><span class="special">(</span><span class="identifier">fcontext_t</span><span class="special">*</span> <span class="identifier">ofc</span><span class="special">,</span><span class="identifier">fcontext_t</span> <span class="identifier">nfc</span><span class="special">,</span><span class="identifier">intptr_t</span> <span class="identifier">p</span><span class="special">,</span><span class="keyword">bool</span>
         <span class="identifier">preserve_fpu</span><span class="special">=</span><span class="keyword">true</span><span class="special">)</span></code></a>
       </h5>
 <div class="variablelist">
 <p class="title"><b></b></p>
-<dl class="variablelist">
+<dl>
 <dt><span class="term">Effects:</span></dt>
 <dd><p>
               Stores the current context data (stack pointer, instruction pointer,
@@ -106,13 +106,13 @@
 </div>
 <h5>
 <a name="context.context.boost_fcontext.h4"></a>
-        <span class="phrase"><a name="context.context.boost_fcontext._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">fcontext_t</span> <span class="identifier">make_fcontext</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span>
+        <span><a name="context.context.boost_fcontext._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="boost_fcontext.html#context.context.boost_fcontext._code__phrase_role__identifier__fcontext_t__phrase___phrase_role__identifier__make_fcontext__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase__phrase_role__keyword__void__phrase__phrase_role__special______phrase__phrase_role__identifier__fn__phrase__phrase_role__special______phrase__phrase_role__identifier__intptr_t__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">fcontext_t</span> <span class="identifier">make_fcontext</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span>
         <span class="identifier">sp</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span>
         <span class="identifier">size</span><span class="special">,</span><span class="keyword">void</span><span class="special">(*</span><span class="identifier">fn</span><span class="special">)(</span><span class="identifier">intptr_t</span><span class="special">))</span></code></a>
       </h5>
 <div class="variablelist">
 <p class="title"><b></b></p>
-<dl class="variablelist">
+<dl>
 <dt><span class="term">Precondition:</span></dt>
 <dd><p>
               Stack <code class="computeroutput"><span class="identifier">sp</span></code> and function
@@ -135,7 +135,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>
@@ -143,7 +143,7 @@
 </tr></table>
 <hr>
 <div class="spirit-nav">
-<a accesskey="p" href="../context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../context.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../performance.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+<a accesskey="p" href="../context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../context.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../econtext.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
 </div>
 </body>
 </html>
diff --git a/libs/context/doc/html/context/econtext.html b/libs/context/doc/html/context/econtext.html
new file mode 100644
index 000000000..e1452a93b
--- /dev/null
+++ b/libs/context/doc/html/context/econtext.html
@@ -0,0 +1,458 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class execution_context</title>
+<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="prev" href="context.html" title="Struct fcontext_t">
+<link rel="next" href="stack.html" title="Stack allocation">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="context.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h2 class="title" style="clear: both">
+<a name="context.econtext"></a><a class="link" href="econtext.html" title="Class execution_context">Class execution_context</a>
+</h2></div></div></div>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+        <span class="emphasis"><em>execution_context</em></span> is supported only by C++14.
+      </p></td></tr>
+</table></div>
+<p>
+      Class <span class="emphasis"><em>execution_context</em></span> encapsulates <span class="emphasis"><em>fcontext_t</em></span>
+      and related functions ( <span class="emphasis"><em>jump_fcontext()</em></span> and <span class="emphasis"><em>make_fcontext()</em></span>)
+      as well as stack management. <span class="emphasis"><em>execution_context</em></span> permits
+      access to the current, active context via <code class="computeroutput"><span class="identifier">execution_context</span><span class="special">::</span><span class="identifier">current</span><span class="special">()</span></code>.
+    </p>
+<pre class="programlisting"><span class="comment">/*
+ * grammar:
+ *   P ---&gt; E '\0'
+ *   E ---&gt; T {('+'|'-') T}
+ *   T ---&gt; S {('*'|'/') S}
+ *   S ---&gt; digit | '(' E ')'
+ */</span>
+<span class="keyword">class</span> <span class="identifier">Parser</span><span class="special">{</span>
+    <span class="comment">// implementation omitted; see examples directory</span>
+<span class="special">};</span>
+
+<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> <span class="special">{</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">istringstream</span> <span class="identifier">is</span><span class="special">(</span><span class="string">"1+1"</span><span class="special">);</span>
+    <span class="keyword">bool</span> <span class="identifier">done</span><span class="special">=</span><span class="keyword">false</span><span class="special">;</span>
+    <span class="keyword">char</span> <span class="identifier">c</span><span class="special">;</span>
+
+    <span class="comment">// create handle to main execution context</span>
+    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">execution_context</span> <span class="identifier">main_ctx</span><span class="special">(</span>
+        <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">execution_context</span><span class="special">::</span><span class="identifier">current</span><span class="special">()</span> <span class="special">);</span>
+
+    <span class="comment">// executes parser in new execution context</span>
+    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">execution_context</span> <span class="identifier">parser_ctx</span><span class="special">(</span>
+        <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">fixedsize_stack</span><span class="special">(),</span>
+        <span class="special">[&amp;</span><span class="identifier">main_ctx</span><span class="special">,&amp;</span><span class="identifier">is</span><span class="special">,&amp;</span><span class="identifier">c</span><span class="special">,&amp;</span><span class="identifier">done</span><span class="special">](){</span>
+            <span class="comment">// create parser with callback function</span>
+            <span class="identifier">Parser</span> <span class="identifier">p</span><span class="special">(</span><span class="identifier">is</span><span class="special">,</span>
+                     <span class="special">[&amp;</span><span class="identifier">main_ctx</span><span class="special">,&amp;</span><span class="identifier">c</span><span class="special">](</span><span class="keyword">char</span> <span class="identifier">ch</span><span class="special">){</span>
+                         <span class="identifier">c</span><span class="special">=</span><span class="identifier">ch</span><span class="special">;</span>
+                         <span class="comment">// resume main execution context</span>
+                         <span class="identifier">main_ctx</span><span class="special">.</span><span class="identifier">resume</span><span class="special">();</span>
+                     <span class="special">});</span>
+            <span class="comment">// start recursive parsing</span>
+            <span class="identifier">p</span><span class="special">.</span><span class="identifier">run</span><span class="special">();</span>
+            <span class="identifier">done</span><span class="special">=</span><span class="keyword">true</span><span class="special">;</span>
+            <span class="comment">// return to main execution context</span>
+            <span class="identifier">main_ctx</span><span class="special">.</span><span class="identifier">resume</span><span class="special">();</span>
+        <span class="special">});</span>
+
+    <span class="comment">// user-code pulls parsed data from parser</span>
+    <span class="comment">// inverted control flow</span>
+    <span class="identifier">parser_ctx</span><span class="special">.</span><span class="identifier">resume</span><span class="special">();</span>
+    <span class="keyword">do</span> <span class="special">{</span>
+        <span class="identifier">printf</span><span class="special">(</span><span class="string">"Parsed: %c\n"</span><span class="special">,</span><span class="identifier">c</span><span class="special">);</span>
+        <span class="identifier">parser_ctx</span><span class="special">.</span><span class="identifier">resume</span><span class="special">();</span>
+    <span class="special">}</span> <span class="keyword">while</span><span class="special">(</span> <span class="special">!</span> <span class="identifier">done</span><span class="special">);</span>
+<span class="special">}</span>
+
+<span class="identifier">output</span><span class="special">:</span>
+    <span class="identifier">Parsed</span><span class="special">:</span> <span class="number">1</span>
+    <span class="identifier">Parsed</span><span class="special">:</span> <span class="special">+</span>
+    <span class="identifier">Parsed</span><span class="special">:</span> <span class="number">1</span>
+</pre>
+<p>
+      In this example a recursive descent parser uses a callback to emit a newly
+      passed symbol. Using <span class="emphasis"><em>execution_context</em></span> the control flow
+      can be inverted, e.g. the user-code pulls parsed symbols from the parser -
+      instead to get pushed from the parser (via callback).
+    </p>
+<p>
+      The interface of <span class="emphasis"><em>execution_context</em></span> does not transfer data.
+      This is not required because usually sharing data's address (pointer/reference)
+      sufficient.
+    </p>
+<p>
+      If the code executed by <span class="emphasis"><em>execution_context</em></span> emits an exception,
+      <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">terminate</span><span class="special">()</span></code>
+      will be called.
+    </p>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+        Do not jump from inside a catch block and than re-throw exceptions in another
+        execution context.
+      </p></td></tr>
+</table></div>
+<p>
+      Sometimes it is necessary to unwind the stack of an unfinished context to destroy
+      local stack variables so they can release allocated resources (RAII pattern).
+      The user is responsible for this task.
+    </p>
+<h4>
+<a name="context.econtext.h0"></a>
+      <span class="phrase"><a name="context.econtext.allocating_control_strutures_on_top_of_stack"></a></span><a class="link" href="econtext.html#context.econtext.allocating_control_strutures_on_top_of_stack">allocating
+      control strutures on top of stack</a>
+    </h4>
+<p>
+      Allocating control structures on top of the stack requires to allocated the
+      <span class="emphasis"><em>stack_context</em></span> and create the control structure with placement
+      new before <span class="emphasis"><em>execution_context</em></span> is created.
+    </p>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+        The user is responsible for destructing the control structure at the top
+        of the stack.
+      </p></td></tr>
+</table></div>
+<pre class="programlisting"><span class="comment">// stack-alloctor used for (de-)allocating stack</span>
+<span class="identifier">fixedsize_stack</span> <span class="identifier">salloc</span><span class="special">(</span> <span class="number">4048</span><span class="special">);</span>
+<span class="comment">// allocate stack space</span>
+<span class="identifier">stack_context</span> <span class="identifier">sctx</span><span class="special">(</span> <span class="identifier">salloc</span><span class="special">.</span><span class="identifier">allocate</span><span class="special">()</span> <span class="special">);</span>
+<span class="comment">// reserve space for control structure on top of the stack</span>
+<span class="keyword">void</span> <span class="special">*</span> <span class="identifier">sp</span> <span class="special">=</span> <span class="keyword">static_cast</span><span class="special">&lt;</span> <span class="keyword">char</span> <span class="special">*</span> <span class="special">&gt;(</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span><span class="special">)</span> <span class="special">-</span> <span class="keyword">sizeof</span><span class="special">(</span> <span class="identifier">my_control_structure</span><span class="special">);</span>
+<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span> <span class="special">-</span> <span class="keyword">sizeof</span><span class="special">(</span> <span class="identifier">my_control_structure</span><span class="special">);</span>
+<span class="comment">// placement new creates control structure on reserved space</span>
+<span class="identifier">my_control_structure</span> <span class="special">*</span> <span class="identifier">cs</span> <span class="special">=</span> <span class="keyword">new</span> <span class="special">(</span> <span class="identifier">sp</span><span class="special">)</span> <span class="identifier">my_control_structure</span><span class="special">(</span> <span class="identifier">sp</span><span class="special">,</span> <span class="identifier">size</span><span class="special">,</span> <span class="identifier">sctx</span><span class="special">,</span> <span class="identifier">salloc</span><span class="special">);</span>
+<span class="special">...</span>
+<span class="comment">// destructing the control structure</span>
+<span class="identifier">cs</span><span class="special">-&gt;~</span><span class="identifier">my_control_structure</span><span class="special">();</span>
+<span class="special">...</span>
+<span class="keyword">struct</span> <span class="identifier">my_control_structure</span>  <span class="special">{</span>
+    <span class="comment">// execution context</span>
+    <span class="identifier">execution_context</span> <span class="identifier">ectx</span><span class="special">;</span>
+
+    <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAllocator</span> <span class="special">&gt;</span>
+    <span class="identifier">my_control_structure</span><span class="special">(</span> <span class="keyword">void</span> <span class="special">*</span> <span class="identifier">sp</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">,</span> <span class="identifier">stack_context</span> <span class="identifier">sctx</span><span class="special">,</span> <span class="identifier">StackAllocator</span> <span class="identifier">salloc</span><span class="special">)</span> <span class="special">:</span>
+        <span class="comment">// create execution context</span>
+        <span class="identifier">ectx</span><span class="special">(</span> <span class="identifier">preallocated</span><span class="special">(</span> <span class="identifier">sp</span><span class="special">,</span> <span class="identifier">size</span><span class="special">,</span> <span class="identifier">sctx</span><span class="special">),</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">entry_func</span><span class="special">)</span> <span class="special">{</span>
+    <span class="special">}</span>
+    <span class="special">...</span>
+<span class="special">};</span>
+</pre>
+<h4>
+<a name="context.econtext.h1"></a>
+      <span class="phrase"><a name="context.econtext.exception_handling"></a></span><a class="link" href="econtext.html#context.econtext.exception_handling">exception
+      handling</a>
+    </h4>
+<p>
+      If the function executed inside a <span class="emphasis"><em>execution_context</em></span> emitts
+      ans exception, <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">terminate</span><span class="special">()</span></code>
+      is called - <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">exception_ptr</span></code> can used to store exceptions
+      thrown inside the other context.
+    </p>
+<h4>
+<a name="context.econtext.h2"></a>
+      <span class="phrase"><a name="context.econtext.parameter_passing"></a></span><a class="link" href="econtext.html#context.econtext.parameter_passing">parameter
+      passing</a>
+    </h4>
+<p>
+      Input and output parameters are transfered via a lambda capture list and references/pointers.
+    </p>
+<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">X</span> <span class="special">{</span>
+<span class="keyword">private</span><span class="special">:</span>
+    <span class="keyword">int</span> <span class="special">*</span> <span class="identifier">inp_</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">outp_</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">exception_ptr</span> <span class="identifier">excptr_</span><span class="special">;</span>
+    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">execution_context</span> <span class="identifier">caller_</span><span class="special">;</span>
+    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">execution_context</span> <span class="identifier">callee_</span><span class="special">;</span>
+
+<span class="keyword">public</span><span class="special">:</span>
+    <span class="identifier">X</span><span class="special">()</span> <span class="special">:</span>
+        <span class="identifier">inp_</span><span class="special">(</span> <span class="keyword">nullptr</span><span class="special">),</span>
+        <span class="identifier">outp_</span><span class="special">(),</span>
+        <span class="identifier">excptr_</span><span class="special">(),</span>
+        <span class="identifier">caller_</span><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">execution_context</span><span class="special">::</span><span class="identifier">current</span><span class="special">()</span> <span class="special">),</span>
+        <span class="identifier">callee_</span><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">context</span><span class="special">::</span><span class="identifier">fixedsize_stack</span><span class="special">(),</span>
+                 <span class="special">[=]</span> <span class="special">()</span> <span class="special">{</span>
+                    <span class="keyword">try</span> <span class="special">{</span>
+                        <span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="special">*</span> <span class="identifier">inp_</span><span class="special">;</span>
+                        <span class="identifier">outp_</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">lexical_cast</span><span class="special">&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">&gt;(</span> <span class="identifier">i</span><span class="special">);</span>
+                        <span class="identifier">caller_</span><span class="special">.</span><span class="identifier">resume</span><span class="special">();</span>
+                    <span class="special">}</span> <span class="keyword">catch</span> <span class="special">(...)</span> <span class="special">{</span>
+                        <span class="identifier">excptr_</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">current_exception</span><span class="special">();</span>
+                    <span class="special">}</span>
+                 <span class="special">})</span>
+    <span class="special">{}</span>
+
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="keyword">operator</span><span class="special">()(</span> <span class="keyword">int</span> <span class="identifier">i</span><span class="special">)</span> <span class="special">{</span>
+        <span class="identifier">inp_</span> <span class="special">=</span> <span class="special">&amp;</span> <span class="identifier">i</span><span class="special">;</span>
+        <span class="identifier">callee_</span><span class="special">.</span><span class="identifier">resume</span><span class="special">();</span>
+        <span class="keyword">if</span> <span class="special">(</span> <span class="identifier">excptr_</span><span class="special">)</span> <span class="special">{</span>
+            <span class="identifier">std</span><span class="special">::</span><span class="identifier">rethrow_exception</span><span class="special">(</span> <span class="identifier">excptr_</span><span class="special">);</span>
+        <span class="special">}</span>
+        <span class="keyword">return</span> <span class="identifier">outp_</span><span class="special">;</span>
+    <span class="special">}</span>
+<span class="special">};</span>
+
+<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> <span class="special">{</span>
+    <span class="identifier">X</span> <span class="identifier">x</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="identifier">x</span><span class="special">(</span> <span class="number">7</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"done"</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
+<span class="special">}</span>
+</pre>
+<h4>
+<a name="context.econtext.h3"></a>
+      <span class="phrase"><a name="context.econtext.class__code__phrase_role__identifier__execution_context__phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext.class__code__phrase_role__identifier__execution_context__phrase___code_">Class
+      <code class="computeroutput"><span class="identifier">execution_context</span></code></a>
+    </h4>
+<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">execution_context</span> <span class="special">{</span>
+<span class="keyword">public</span><span class="special">:</span>
+    <span class="keyword">static</span> <span class="identifier">execution_context</span> <span class="identifier">current</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Fn</span> <span class="special">&gt;</span>
+    <span class="identifier">execution_context</span><span class="special">(</span> <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span> <span class="identifier">fn</span><span class="special">);</span>
+
+    <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Fn</span><span class="special">,</span> <span class="keyword">typename</span> <span class="special">...</span> <span class="identifier">Args</span> <span class="special">&gt;</span>
+    <span class="identifier">execution_context</span><span class="special">(</span> <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span> <span class="identifier">fn</span><span class="special">,</span> <span class="identifier">Args</span> <span class="special">&amp;&amp;</span> <span class="special">...</span> <span class="identifier">args</span><span class="special">);</span>
+
+    <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Fn</span> <span class="special">&gt;</span>
+    <span class="identifier">execution_context</span><span class="special">(</span> <span class="identifier">preallocated</span> <span class="identifier">palloc</span><span class="special">,</span> <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span> <span class="identifier">fn</span><span class="special">);</span>
+
+    <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Fn</span><span class="special">,</span> <span class="keyword">typename</span> <span class="special">...</span> <span class="identifier">Args</span> <span class="special">&gt;</span>
+    <span class="identifier">execution_context</span><span class="special">(</span> <span class="identifier">preallocated</span> <span class="identifier">palloc</span><span class="special">,</span> <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span> <span class="identifier">fn</span><span class="special">,</span> <span class="identifier">Args</span> <span class="special">&amp;&amp;</span> <span class="special">...</span> <span class="identifier">args</span><span class="special">);</span>
+
+    <span class="keyword">void</span> <span class="identifier">resume</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">explicit</span> <span class="keyword">operator</span> <span class="keyword">bool</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span>
+<span class="special">};</span>
+</pre>
+<h4>
+<a name="context.econtext.h4"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__static__phrase___phrase_role__identifier__execution_context__phrase___phrase_role__identifier__current__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__static__phrase___phrase_role__identifier__execution_context__phrase___phrase_role__identifier__current__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">execution_context</span>
+      <span class="identifier">current</span><span class="special">()</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+            Returns an instance of excution_context pointing to the active execution
+            context.
+          </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+            Nothing.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h5"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="identifier">typname</span> <span class="identifier">Fn</span> <span class="special">&gt;</span> <span class="identifier">execution_context</span><span class="special">(</span>
+      <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span>
+      <span class="identifier">fn</span><span class="special">)</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Creates a new execution context and prepares the context to execute
+            <code class="computeroutput"><span class="identifier">fn</span></code>.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h6"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="identifier">typname</span> <span class="identifier">Fn</span><span class="special">,</span> <span class="keyword">typename</span>
+      <span class="special">...</span> <span class="identifier">Args</span>
+      <span class="special">&gt;</span> <span class="identifier">execution_context</span><span class="special">(</span> <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span> <span class="identifier">fn</span><span class="special">,</span> <span class="identifier">Args</span>
+      <span class="special">&amp;&amp;</span> <span class="special">...</span>
+      <span class="identifier">args</span><span class="special">)</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Creates a new execution context and prepares the context to execute
+            <code class="computeroutput"><span class="identifier">fn</span></code>.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h7"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="identifier">typname</span> <span class="identifier">Fn</span> <span class="special">&gt;</span> <span class="identifier">execution_context</span><span class="special">(</span>
+      <span class="identifier">preallocated</span> <span class="identifier">palloc</span><span class="special">,</span> <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span> <span class="identifier">fn</span><span class="special">)</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Creates a new execution context and prepares the context to execute
+            <code class="computeroutput"><span class="identifier">fn</span></code>. Used to store control
+            structures on top of the stack.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h8"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__template__phrase__phrase_role__special___lt___phrase___phrase_role__keyword__typename__phrase___phrase_role__identifier__stackalloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__typname__phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__keyword__typename__phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase___phrase_role__special___gt___phrase___phrase_role__identifier__execution_context__phrase__phrase_role__special_____phrase___phrase_role__identifier__preallocated__phrase___phrase_role__identifier__palloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__stackalloc__phrase___phrase_role__identifier__salloc__phrase__phrase_role__special_____phrase___phrase_role__identifier__fn__phrase___phrase_role__special___amp__amp___phrase___phrase_role__identifier__fn__phrase__phrase_role__special_____phrase___phrase_role__identifier__args__phrase___phrase_role__special___amp__amp___phrase___phrase_role__special_______phrase___phrase_role__identifier__args__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">StackAlloc</span><span class="special">,</span> <span class="identifier">typname</span> <span class="identifier">Fn</span><span class="special">,</span> <span class="keyword">typename</span>
+      <span class="special">...</span> <span class="identifier">Args</span>
+      <span class="special">&gt;</span> <span class="identifier">execution_context</span><span class="special">(</span> <span class="identifier">preallocated</span>
+      <span class="identifier">palloc</span><span class="special">,</span>
+      <span class="identifier">StackAlloc</span> <span class="identifier">salloc</span><span class="special">,</span> <span class="identifier">Fn</span> <span class="special">&amp;&amp;</span>
+      <span class="identifier">fn</span><span class="special">,</span> <span class="identifier">Args</span> <span class="special">&amp;&amp;</span>
+      <span class="special">...</span> <span class="identifier">args</span><span class="special">)</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Creates a new execution context and prepares the context to execute
+            <code class="computeroutput"><span class="identifier">fn</span></code>. Used to store control
+            structures on top of the stack.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h9"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__void__phrase___phrase_role__identifier__resume__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__void__phrase___phrase_role__identifier__resume__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">resume</span><span class="special">()</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Stores internally the current context data (stack pointer, instruction
+            pointer, and CPU registers) to the current active context and restores
+            the context data from <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>, which implies jumping to <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>'s
+            execution context.
+          </p></dd>
+<dt><span class="term">Note:</span></dt>
+<dd><p>
+            The behaviour is undefined if <code class="computeroutput"><span class="identifier">resume</span><span class="special">()</span></code> is called while <code class="computeroutput"><span class="identifier">execution_context</span><span class="special">::</span><span class="identifier">current</span><span class="special">()</span></code> returns <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> (e.g. resuming an alredy running
+            cotnext).
+          </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+            Nothing.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h10"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__explicit__phrase___phrase_role__keyword__operator__phrase___phrase_role__keyword__bool__phrase__phrase_role__special______phrase___phrase_role__keyword__const__phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__explicit__phrase___phrase_role__keyword__operator__phrase___phrase_role__keyword__bool__phrase__phrase_role__special______phrase___phrase_role__keyword__const__phrase___code_"><code class="computeroutput"><span class="keyword">explicit</span> <span class="keyword">operator</span>
+      <span class="keyword">bool</span><span class="special">()</span> <span class="keyword">const</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+            If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
+            refers to an invalid context or the context-function has returned (completed),
+            the function returns <code class="computeroutput"><span class="keyword">false</span></code>.
+            Otherwise <code class="computeroutput"><span class="keyword">true</span></code>.
+          </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+            Nothing.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h11"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__keyword__bool__phrase___phrase_role__keyword__operator__phrase__phrase_role__special_______phrase___phrase_role__keyword__const__phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__keyword__bool__phrase___phrase_role__keyword__operator__phrase__phrase_role__special_______phrase___phrase_role__keyword__const__phrase___code_"><code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">const</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+            If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
+            refers to an invalid context or the context-function has returned (completed),
+            the function returns <code class="computeroutput"><span class="keyword">true</span></code>.
+            Otherwise <code class="computeroutput"><span class="keyword">false</span></code>.
+          </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+            Nothing.
+          </p></dd>
+</dl>
+</div>
+<h4>
+<a name="context.econtext.h12"></a>
+      <span class="phrase"><a name="context.econtext.struct__code__phrase_role__identifier__preallocated__phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext.struct__code__phrase_role__identifier__preallocated__phrase___code_">Struct
+      <code class="computeroutput"><span class="identifier">preallocated</span></code></a>
+    </h4>
+<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">preallocated</span> <span class="special">{</span>
+    <span class="keyword">void</span>        <span class="special">*</span>   <span class="identifier">sp</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span>     <span class="identifier">size</span><span class="special">;</span>
+    <span class="identifier">stack_context</span>   <span class="identifier">sctx</span><span class="special">;</span>
+
+    <span class="identifier">preallocated</span><span class="special">(</span> <span class="keyword">void</span> <span class="special">*</span> <span class="identifier">sp</span><span class="special">,</span> <span class="identifier">std</span><span class="special">:</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">,</span> <span class="identifier">stack_allocator</span> <span class="identifier">sctx</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
+<span class="special">};</span>
+</pre>
+<h4>
+<a name="context.econtext.h13"></a>
+      <span class="phrase"><a name="context.econtext._code__phrase_role__identifier__preallocated__phrase__phrase_role__special_____phrase___phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special_____phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_allocator__phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="econtext.html#context.econtext._code__phrase_role__identifier__preallocated__phrase__phrase_role__special_____phrase___phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase__phrase_role__special_____phrase___phrase_role__identifier__std__phrase__phrase_role__special_____phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_allocator__phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="identifier">preallocated</span><span class="special">(</span> <span class="keyword">void</span> <span class="special">*</span> <span class="identifier">sp</span><span class="special">,</span> <span class="identifier">std</span><span class="special">:</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">,</span> <span class="identifier">stack_allocator</span>
+      <span class="identifier">sctx</span><span class="special">)</span></code></a>
+    </h4>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+            Crreates an object of preallocated.
+          </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="context.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/acknowledgements.html b/libs/context/doc/html/context/econtext/acknowledgements.html
new file mode 100644
index 000000000..e9a60c988
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/acknowledgements.html
@@ -0,0 +1,49 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Acknowledgments</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../econtext.html" title="Execution context">
+<link rel="prev" href="reference.html" title="Reference">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.econtext.acknowledgements"></a><a class="link" href="acknowledgements.html" title="Acknowledgments">Acknowledgments</a>
+</h3></div></div></div>
+<p>
+        I'd like to thank Adreas Fett, Artyom Beilis, Daniel Larimer, David Deakins,
+        Evgeny Shapovalov, Fernando Pelliccioni, Giovanni Piero Deretta, Gordon Woodhull,
+        Helge Bahmann, Holger Grund, Jeffrey Lee Hellrung (Jr.), Keith Jeffery, Martin
+        Husemann, Phil Endecott, Robert Stewart, Sergey Cheban, Steven Watanabe,
+        Vicente J. Botet Escriba, Wayne Piekarski.
+      </p>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="reference.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/architectures.html b/libs/context/doc/html/context/econtext/architectures.html
new file mode 100644
index 000000000..201d252be
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/architectures.html
@@ -0,0 +1,277 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Architectures</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../econtext.html" title="Execution context">
+<link rel="prev" href="performance.html" title="Performance">
+<link rel="next" href="rationale.html" title="Rationale">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="performance.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rationale.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.econtext.architectures"></a><a class="link" href="architectures.html" title="Architectures">Architectures</a>
+</h3></div></div></div>
+<p>
+        <span class="bold"><strong>Boost.Context</strong></span> supports following architectures:
+      </p>
+<div class="table">
+<a name="context.econtext.architectures.supported_architectures___abi_binary_format__"></a><p class="title"><b>Table&#160;1.2.&#160;Supported architectures (&lt;ABI|binary format&gt;)</b></p>
+<div class="table-contents"><table class="table" summary="Supported architectures (&lt;ABI|binary format&gt;)">
+<colgroup>
+<col>
+<col>
+<col>
+<col>
+<col>
+</colgroup>
+<thead><tr>
+<th>
+                <p>
+                  Architecture
+                </p>
+              </th>
+<th>
+                <p>
+                  LINUX (UNIX)
+                </p>
+              </th>
+<th>
+                <p>
+                  Windows
+                </p>
+              </th>
+<th>
+                <p>
+                  MacOS X
+                </p>
+              </th>
+<th>
+                <p>
+                  iOS
+                </p>
+              </th>
+</tr></thead>
+<tbody>
+<tr>
+<td>
+                <p>
+                  arm
+                </p>
+              </td>
+<td>
+                <p>
+                  AAPCS|ELF
+                </p>
+              </td>
+<td>
+                <p>
+                  AAPCS|PE
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  AAPCS|MACH-O
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  i386
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV|ELF
+                </p>
+              </td>
+<td>
+                <p>
+                  MS|PE
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV|MACH-O
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  mips1
+                </p>
+              </td>
+<td>
+                <p>
+                  O32|ELF
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  ppc32
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV|ELF,XCOFF
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV|MACH-O
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  ppc64
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV|ELF,XCOFF
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV|MACH-O
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  sparc
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  x86_64
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV,X32|ELF
+                </p>
+              </td>
+<td>
+                <p>
+                  MS|PE
+                </p>
+              </td>
+<td>
+                <p>
+                  SYSV|MACH-O
+                </p>
+              </td>
+<td>
+                <p>
+                  -
+                </p>
+              </td>
+</tr>
+</tbody>
+</table></div>
+</div>
+<br class="table-break">
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="performance.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rationale.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/performance.html b/libs/context/doc/html/context/econtext/performance.html
new file mode 100644
index 000000000..9dbe3c8c1
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/performance.html
@@ -0,0 +1,139 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Performance</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../econtext.html" title="Execution context">
+<link rel="prev" href="stack/stack_context.html" title="Class stack_context">
+<link rel="next" href="architectures.html" title="Architectures">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack/stack_context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="architectures.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.econtext.performance"></a><a class="link" href="performance.html" title="Performance">Performance</a>
+</h3></div></div></div>
+<p>
+        Performance of <span class="bold"><strong>Boost.Context</strong></span> was measured
+        on the platforms shown in the following table. Performance measurements were
+        taken using <code class="computeroutput"><span class="identifier">rdtsc</span></code> and <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">chrono</span><span class="special">::</span><span class="identifier">high_resolution_clock</span></code>, with overhead corrections,
+        on x86 platforms. In each case, cache warm-up was accounted for, and the
+        one running thread was pinned to a single CPU. The code was compiled using
+        the build options, 'variant = release cxxflags = -DBOOST_DISABLE_ASSERTS'.
+      </p>
+<div class="table">
+<a name="context.econtext.performance.performance_of_context_switch"></a><p class="title"><b>Table&#160;1.1.&#160;Performance of context switch</b></p>
+<div class="table-contents"><table class="table" summary="Performance of context switch">
+<colgroup>
+<col>
+<col>
+<col>
+<col>
+</colgroup>
+<thead><tr>
+<th>
+                <p>
+                  Platform
+                </p>
+              </th>
+<th>
+                <p>
+                  ucontext_t
+                </p>
+              </th>
+<th>
+                <p>
+                  fcontext_t
+                </p>
+              </th>
+<th>
+                <p>
+                  windows fibers
+                </p>
+              </th>
+</tr></thead>
+<tbody>
+<tr>
+<td>
+                <p>
+                  i386 <sup>[<a name="context.econtext.performance.f0" href="#ftn.context.econtext.performance.f0" class="footnote">a</a>]</sup>
+                </p>
+              </td>
+<td>
+                <p>
+                  708 ns / 754 cycles
+                </p>
+              </td>
+<td>
+                <p>
+                  37 ns / 37 cycles
+                </p>
+              </td>
+<td>
+                <p>
+                  ns / cycles
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  x86_64 <sup>[<a name="context.econtext.performance.f1" href="#ftn.context.econtext.performance.f1" class="footnote">b</a>]</sup>
+                </p>
+              </td>
+<td>
+                <p>
+                  547 ns / 1433 cycles
+                </p>
+              </td>
+<td>
+                <p>
+                  8 ns / 23 cycles
+                </p>
+              </td>
+<td>
+                <p>
+                  ns / cycles
+                </p>
+              </td>
+</tr>
+</tbody>
+<tbody class="footnotes"><tr><td colspan="4">
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.performance.f0" href="#context.econtext.performance.f0" class="para">a</a>] </sup>
+                    AMD Athlon 64 DualCore 4400+
+                  </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.performance.f1" href="#context.econtext.performance.f1" class="para">b</a>] </sup>
+                    Intel Core2 Q6700
+                  </p></div>
+</td></tr></tbody>
+</table></div>
+</div>
+<br class="table-break">
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack/stack_context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="architectures.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/rationale.html b/libs/context/doc/html/context/econtext/rationale.html
new file mode 100644
index 000000000..a7674b4fd
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/rationale.html
@@ -0,0 +1,87 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Rationale</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../econtext.html" title="Execution context">
+<link rel="prev" href="architectures.html" title="Architectures">
+<link rel="next" href="rationale/other_apis_.html" title="Other APIs">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="architectures.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rationale/other_apis_.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.econtext.rationale"></a><a class="link" href="rationale.html" title="Rationale">Rationale</a>
+</h3></div></div></div>
+<div class="toc"><dl>
+<dt><span class="section"><a href="rationale/other_apis_.html">Other APIs
+        </a></span></dt>
+<dt><span class="section"><a href="rationale/x86_and_floating_point_env.html">x86
+        and floating-point env</a></span></dt>
+</dl></div>
+<h5>
+<a name="context.econtext.rationale.h0"></a>
+        <span><a name="context.econtext.rationale.no_inline_assembler"></a></span><a class="link" href="rationale.html#context.econtext.rationale.no_inline_assembler">No
+        inline-assembler</a>
+      </h5>
+<p>
+        Some newer compiler (for instance MSVC 10 for x86_64 and itanium) do not
+        support inline assembler. <sup>[<a name="context.econtext.rationale.f0" href="#ftn.context.econtext.rationale.f0" class="footnote">1</a>]</sup>. Inlined assembler generates code bloating which his not welcome
+        on embedded systems.
+      </p>
+<h5>
+<a name="context.econtext.rationale.h1"></a>
+        <span><a name="context.econtext.rationale.fcontext_t"></a></span><a class="link" href="rationale.html#context.econtext.rationale.fcontext_t">fcontext_t</a>
+      </h5>
+<p>
+        <span class="bold"><strong>Boost.Context</strong></span> provides the low level API
+        fcontext_t which is implemented in assembler to provide context swapping
+        operations. fcontext_t is the part to port to new platforms.
+      </p>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          Context switches do not preserve the signal mask on UNIX systems.
+        </p></td></tr>
+</table></div>
+<p>
+        <span class="emphasis"><em>fcontext_t</em></span> is an opaque pointer.
+      </p>
+<div class="footnotes">
+<br><hr width="100" align="left">
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.f0" href="#context.econtext.rationale.f0" class="para">1</a>] </sup>
+          <a href="http://msdn.microsoft.com/en-us/library/4ks26t93.aspx" target="_top">MSDN
+          article 'Inline Assembler'</a>
+        </p></div>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="architectures.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="rationale/other_apis_.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/rationale/other_apis_.html b/libs/context/doc/html/context/econtext/rationale/other_apis_.html
new file mode 100644
index 000000000..194d3e88c
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/rationale/other_apis_.html
@@ -0,0 +1,119 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Other APIs</title>
+<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../rationale.html" title="Rationale">
+<link rel="prev" href="../rationale.html" title="Rationale">
+<link rel="next" href="x86_and_floating_point_env.html" title="x86 and floating-point env">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../rationale.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../rationale.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="x86_and_floating_point_env.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h4 class="title">
+<a name="context.econtext.rationale.other_apis_"></a><a class="link" href="other_apis_.html" title="Other APIs">Other APIs
+        </a>
+</h4></div></div></div>
+<h6>
+<a name="context.econtext.rationale.other_apis_.h0"></a>
+          <span><a name="context.econtext.rationale.other_apis_.setjmp___longjmp__"></a></span><a class="link" href="other_apis_.html#context.econtext.rationale.other_apis_.setjmp___longjmp__">setjmp()/longjmp()</a>
+        </h6>
+<p>
+          C99 defines <code class="computeroutput"><span class="identifier">setjmp</span><span class="special">()</span></code>/<code class="computeroutput"><span class="identifier">longjmp</span><span class="special">()</span></code>
+          to provide non-local jumps but it does not require that <span class="emphasis"><em>longjmp()</em></span>
+          preserves the current stack frame. Therefore, jumping into a function which
+          was exited via a call to <span class="emphasis"><em>longjmp()</em></span> is undefined <sup>[<a name="context.econtext.rationale.other_apis_.f0" href="#ftn.context.econtext.rationale.other_apis_.f0" class="footnote">2</a>]</sup>.
+        </p>
+<h6>
+<a name="context.econtext.rationale.other_apis_.h1"></a>
+          <span><a name="context.econtext.rationale.other_apis_.ucontext_t"></a></span><a class="link" href="other_apis_.html#context.econtext.rationale.other_apis_.ucontext_t">ucontext_t</a>
+        </h6>
+<p>
+          Since POSIX.1-2003 <code class="computeroutput"><span class="identifier">ucontext_t</span></code>
+          is deprecated and was removed in POSIX.1-2008! The function signature of
+          <code class="computeroutput"><span class="identifier">makecontext</span><span class="special">()</span></code>
+          is:
+        </p>
+<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">makecontext</span><span class="special">(</span><span class="identifier">ucontext_t</span> <span class="special">*</span><span class="identifier">ucp</span><span class="special">,</span> <span class="keyword">void</span> <span class="special">(*</span><span class="identifier">func</span><span class="special">)(),</span> <span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="special">...);</span>
+</pre>
+<p>
+          The third argument of <code class="computeroutput"><span class="identifier">makecontext</span><span class="special">()</span></code> specifies the number of integer arguments
+          that follow which will require function pointer cast if <code class="computeroutput"><span class="identifier">func</span></code>
+          will accept those arguments which is undefined in C99 <sup>[<a name="context.econtext.rationale.other_apis_.f1" href="#ftn.context.econtext.rationale.other_apis_.f1" class="footnote">3</a>]</sup>.
+        </p>
+<p>
+          The arguments in the var-arg list are required to be integers, passing
+          pointers in var-arg list is not guaranteed to work, especially it will
+          fail for architectures where pointers are larger than integers.
+        </p>
+<p>
+          <code class="computeroutput"><span class="identifier">ucontext_t</span></code> preserves signal
+          mask between context switches which involves system calls consuming a lot
+          of CPU cycles (ucontext_t is slower by perfomance_link[factor 13x] relative
+          to <code class="computeroutput"><span class="identifier">fcontext_t</span></code>).
+        </p>
+<h6>
+<a name="context.econtext.rationale.other_apis_.h2"></a>
+          <span><a name="context.econtext.rationale.other_apis_.windows_fibers"></a></span><a class="link" href="other_apis_.html#context.econtext.rationale.other_apis_.windows_fibers">Windows
+          fibers</a>
+        </h6>
+<p>
+          A drawback of Windows Fiber API is that <code class="computeroutput"><span class="identifier">CreateFiber</span><span class="special">()</span></code> does not accept a pointer to user allocated
+          stack space preventing the reuse of stacks for other context instances.
+          Because the Windows Fiber API requires to call <code class="computeroutput"><span class="identifier">ConvertThreadToFiber</span><span class="special">()</span></code> if <code class="computeroutput"><span class="identifier">SwitchFiber</span><span class="special">()</span></code> is called for a thread which has not
+          been converted to a fiber. For the same reason <code class="computeroutput"><span class="identifier">ConvertFiberToThread</span><span class="special">()</span></code> must be called after return from <code class="computeroutput"><span class="identifier">SwitchFiber</span><span class="special">()</span></code>
+          if the thread was forced to be converted to a fiber before (which is inefficient).
+        </p>
+<pre class="programlisting"><span class="keyword">if</span> <span class="special">(</span> <span class="special">!</span> <span class="identifier">is_a_fiber</span><span class="special">()</span> <span class="special">)</span>
+<span class="special">{</span>
+    <span class="identifier">ConvertThreadToFiber</span><span class="special">(</span> <span class="number">0</span><span class="special">);</span>
+    <span class="identifier">SwitchToFiber</span><span class="special">(</span> <span class="identifier">ctx</span><span class="special">);</span>
+    <span class="identifier">ConvertFiberToThread</span><span class="special">();</span>
+<span class="special">}</span>
+</pre>
+<p>
+          If the condition <code class="computeroutput"><span class="identifier">_WIN32_WINNT</span>
+          <span class="special">&gt;=</span> <span class="identifier">_WIN32_WINNT_VISTA</span></code>
+          is met function <code class="computeroutput"><span class="identifier">IsThreadAFiber</span><span class="special">()</span></code> is provided in order to detect if the
+          current thread was already converted. Unfortunately Windows XP + SP 2/3
+          defines <code class="computeroutput"><span class="identifier">_WIN32_WINNT</span> <span class="special">&gt;=</span>
+          <span class="identifier">_WIN32_WINNT_VISTA</span></code> without providing
+          <code class="computeroutput"><span class="identifier">IsThreadAFiber</span><span class="special">()</span></code>.
+        </p>
+<div class="footnotes">
+<br><hr width="100" align="left">
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.other_apis_.f0" href="#context.econtext.rationale.other_apis_.f0" class="para">2</a>] </sup>
+            ISO/IEC 9899:1999, 2005, 7.13.2.1:2
+          </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.other_apis_.f1" href="#context.econtext.rationale.other_apis_.f1" class="para">3</a>] </sup>
+            ISO/IEC 9899:1999, 2005, J.2
+          </p></div>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../rationale.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../rationale.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="x86_and_floating_point_env.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/rationale/x86_and_floating_point_env.html b/libs/context/doc/html/context/econtext/rationale/x86_and_floating_point_env.html
new file mode 100644
index 000000000..201b6e43c
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/rationale/x86_and_floating_point_env.html
@@ -0,0 +1,124 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>x86 and floating-point env</title>
+<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../rationale.html" title="Rationale">
+<link rel="prev" href="other_apis_.html" title="Other APIs">
+<link rel="next" href="../reference.html" title="Reference">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="other_apis_.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../rationale.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../reference.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h4 class="title">
+<a name="context.econtext.rationale.x86_and_floating_point_env"></a><a class="link" href="x86_and_floating_point_env.html" title="x86 and floating-point env">x86
+        and floating-point env</a>
+</h4></div></div></div>
+<h6>
+<a name="context.econtext.rationale.x86_and_floating_point_env.h0"></a>
+          <span><a name="context.econtext.rationale.x86_and_floating_point_env.i386"></a></span><a class="link" href="x86_and_floating_point_env.html#context.econtext.rationale.x86_and_floating_point_env.i386">i386</a>
+        </h6>
+<p>
+          "The FpCsr and the MxCsr register must be saved and restored before
+          any call or return by any procedure that needs to modify them ..."
+          <sup>[<a name="context.econtext.rationale.x86_and_floating_point_env.f0" href="#ftn.context.econtext.rationale.x86_and_floating_point_env.f0" class="footnote">4</a>]</sup>.
+        </p>
+<h6>
+<a name="context.econtext.rationale.x86_and_floating_point_env.h1"></a>
+          <span><a name="context.econtext.rationale.x86_and_floating_point_env.x86_64"></a></span><a class="link" href="x86_and_floating_point_env.html#context.econtext.rationale.x86_and_floating_point_env.x86_64">x86_64</a>
+        </h6>
+<h6>
+<a name="context.econtext.rationale.x86_and_floating_point_env.h2"></a>
+          <span><a name="context.econtext.rationale.x86_and_floating_point_env.windows"></a></span><a class="link" href="x86_and_floating_point_env.html#context.econtext.rationale.x86_and_floating_point_env.windows">Windows</a>
+        </h6>
+<p>
+          MxCsr - "A callee that modifies any of the non-volatile fields within
+          MxCsr must restore them before returning to its caller. Furthermore, a
+          caller that has modified any of these fields must restore them to their
+          standard values before invoking a callee ..." <sup>[<a name="context.econtext.rationale.x86_and_floating_point_env.f1" href="#ftn.context.econtext.rationale.x86_and_floating_point_env.f1" class="footnote">5</a>]</sup>.
+        </p>
+<p>
+          FpCsr - "A callee that modifies any of the fields within FpCsr must
+          restore them before returning to its caller. Furthermore, a caller that
+          has modified any of these fields must restore them to their standard values
+          before invoking a callee ..." <sup>[<a name="context.econtext.rationale.x86_and_floating_point_env.f2" href="#ftn.context.econtext.rationale.x86_and_floating_point_env.f2" class="footnote">6</a>]</sup>.
+        </p>
+<p>
+          "The MMX and floating-point stack registers (MM0-MM7/ST0-ST7) are
+          preserved across context switches. There is no explicit calling convention
+          for these registers." <sup>[<a name="context.econtext.rationale.x86_and_floating_point_env.f3" href="#ftn.context.econtext.rationale.x86_and_floating_point_env.f3" class="footnote">7</a>]</sup>.
+        </p>
+<p>
+          "The 64-bit Microsoft compiler does not use ST(0)-ST(7)/MM0-MM7".
+          <sup>[<a name="context.econtext.rationale.x86_and_floating_point_env.f4" href="#ftn.context.econtext.rationale.x86_and_floating_point_env.f4" class="footnote">8</a>]</sup>.
+        </p>
+<p>
+          "XMM6-XMM15 must be preserved" <sup>[<a name="context.econtext.rationale.x86_and_floating_point_env.f5" href="#ftn.context.econtext.rationale.x86_and_floating_point_env.f5" class="footnote">9</a>]</sup>
+        </p>
+<h6>
+<a name="context.econtext.rationale.x86_and_floating_point_env.h3"></a>
+          <span><a name="context.econtext.rationale.x86_and_floating_point_env.sysv"></a></span><a class="link" href="x86_and_floating_point_env.html#context.econtext.rationale.x86_and_floating_point_env.sysv">SysV</a>
+        </h6>
+<p>
+          "The control bits of the MxCsr register are callee-saved (preserved
+          across calls), while the status bits are caller-saved (not preserved).
+          The x87 status word register is caller-saved, whereas the x87 control word
+          (FpCsr) is callee-saved." <sup>[<a name="context.econtext.rationale.x86_and_floating_point_env.f6" href="#ftn.context.econtext.rationale.x86_and_floating_point_env.f6" class="footnote">10</a>]</sup>.
+        </p>
+<div class="footnotes">
+<br><hr width="100" align="left">
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.x86_and_floating_point_env.f0" href="#context.econtext.rationale.x86_and_floating_point_env.f0" class="para">4</a>] </sup>
+            'Calling Conventions', Agner Fog
+          </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.x86_and_floating_point_env.f1" href="#context.econtext.rationale.x86_and_floating_point_env.f1" class="para">5</a>] </sup>
+            <a href="http://http://msdn.microsoft.com/en-us/library/yxty7t75.aspx" target="_top">MSDN
+            article 'MxCsr'</a>
+          </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.x86_and_floating_point_env.f2" href="#context.econtext.rationale.x86_and_floating_point_env.f2" class="para">6</a>] </sup>
+            <a href="http://http://msdn.microsoft.com/en-us/library/ms235300.aspx" target="_top">MSDN
+            article 'FpCsr'</a>
+          </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.x86_and_floating_point_env.f3" href="#context.econtext.rationale.x86_and_floating_point_env.f3" class="para">7</a>] </sup>
+            <a href="http://msdn.microsoft.com/en-us/library/a32tsf7t%28VS.80%29.aspx" target="_top">MSDN
+            article 'Legacy Floating-Point Support'</a>
+          </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.x86_and_floating_point_env.f4" href="#context.econtext.rationale.x86_and_floating_point_env.f4" class="para">8</a>] </sup>
+            'Calling Conventions', Agner Fog
+          </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.x86_and_floating_point_env.f5" href="#context.econtext.rationale.x86_and_floating_point_env.f5" class="para">9</a>] </sup>
+            <a href="http://msdn.microsoft.com/en-us/library/9z1stfyw%28v=vs.100%29.aspx" target="_top">MSDN
+            article 'Register Usage'</a>
+          </p></div>
+<div class="footnote"><p><sup>[<a name="ftn.context.econtext.rationale.x86_and_floating_point_env.f6" href="#context.econtext.rationale.x86_and_floating_point_env.f6" class="para">10</a>] </sup>
+            SysV ABI AMD64 Architecture Processor Supplement Draft Version 0.99.4,
+            3.2.1
+          </p></div>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="other_apis_.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../rationale.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../reference.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/reference.html b/libs/context/doc/html/context/econtext/reference.html
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index 000000000..509e43b8e
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@@ -0,0 +1,104 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Reference</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../econtext.html" title="Execution context">
+<link rel="prev" href="rationale/x86_and_floating_point_env.html" title="x86 and floating-point env">
+<link rel="next" href="acknowledgements.html" title="Acknowledgments">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="rationale/x86_and_floating_point_env.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="acknowledgements.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.econtext.reference"></a><a class="link" href="reference.html" title="Reference">Reference</a>
+</h3></div></div></div>
+<h5>
+<a name="context.econtext.reference.h0"></a>
+        <span><a name="context.econtext.reference.arm"></a></span><a class="link" href="reference.html#context.econtext.reference.arm">ARM</a>
+      </h5>
+<div class="itemizedlist"><ul class="itemizedlist" type="disc">
+<li class="listitem">
+            AAPCS ABI: Procedure Call Standard for the ARM Architecture
+          </li>
+<li class="listitem">
+            AAPCS/LINUX: ARM GNU/Linux Application Binary Interface Supplement
+          </li>
+</ul></div>
+<h5>
+<a name="context.econtext.reference.h1"></a>
+        <span><a name="context.econtext.reference.mips"></a></span><a class="link" href="reference.html#context.econtext.reference.mips">MIPS</a>
+      </h5>
+<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
+            O32 ABI: SYSTEM V APPLICATION BINARY INTERFACE, MIPS RISC Processor Supplement
+          </li></ul></div>
+<h5>
+<a name="context.econtext.reference.h2"></a>
+        <span><a name="context.econtext.reference.powerpc32"></a></span><a class="link" href="reference.html#context.econtext.reference.powerpc32">PowerPC32</a>
+      </h5>
+<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
+            SYSV ABI: SYSTEM V APPLICATION BINARY INTERFACE PowerPC Processor Supplement
+          </li></ul></div>
+<h5>
+<a name="context.econtext.reference.h3"></a>
+        <span><a name="context.econtext.reference.powerpc64"></a></span><a class="link" href="reference.html#context.econtext.reference.powerpc64">PowerPC64</a>
+      </h5>
+<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
+            SYSV ABI: PowerPC User Instruction Set Architecture, Book I
+          </li></ul></div>
+<h5>
+<a name="context.econtext.reference.h4"></a>
+        <span><a name="context.econtext.reference.x86_32"></a></span><a class="link" href="reference.html#context.econtext.reference.x86_32">X86-32</a>
+      </h5>
+<div class="itemizedlist"><ul class="itemizedlist" type="disc">
+<li class="listitem">
+            SYSV ABI: SYSTEM V APPLICATION BINARY INTERFACE, Intel386TM Architecture
+            Processor Supplement
+          </li>
+<li class="listitem">
+            MS PE: <a href="http://msdn.microsoft.com/en-us/library/k2b2ssfy.aspx" target="_top">Calling
+            Conventions</a>
+          </li>
+</ul></div>
+<h5>
+<a name="context.econtext.reference.h5"></a>
+        <span><a name="context.econtext.reference.x86_64"></a></span><a class="link" href="reference.html#context.econtext.reference.x86_64">X86-64</a>
+      </h5>
+<div class="itemizedlist"><ul class="itemizedlist" type="disc">
+<li class="listitem">
+            SYSV ABI: System V Application Binary Interface, AMD64 Architecture Processor
+            Supplement
+          </li>
+<li class="listitem">
+            MS PE: <a href="http://msdn.microsoft.com/en-us/library/7kcdt6fy%28VS.80%29.aspx" target="_top">x64
+            Software Conventions</a>
+          </li>
+</ul></div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="rationale/x86_and_floating_point_env.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="acknowledgements.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
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@@ -0,0 +1,184 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Stack allocation</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
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+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../econtext.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack/protected_fixedsize.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.econtext.stack"></a><a class="link" href="stack.html" title="Stack allocation">Stack allocation</a>
+</h3></div></div></div>
+<div class="toc"><dl>
+<dt><span class="section"><a href="stack/protected_fixedsize.html">Class
+        <span class="emphasis"><em>protected_fixedsize</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/fixedsize.html">Class <span class="emphasis"><em>fixedsize</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/segmented.html">Class <span class="emphasis"><em>segmented</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/stack_traits.html">Class <span class="emphasis"><em>stack_traits</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/stack_context.html">Class <span class="emphasis"><em>stack_context</em></span></a></span></dt>
+</dl></div>
+<p>
+        The memory used by the stack is allocated/deallocated via a <span class="emphasis"><em>StackAllocator</em></span>
+        which is required to model a <span class="emphasis"><em>stack-allocator concept</em></span>.
+      </p>
+<h5>
+<a name="context.econtext.stack.h0"></a>
+        <span><a name="context.econtext.stack._emphasis_stack_allocator_concept__emphasis_"></a></span><a class="link" href="stack.html#context.econtext.stack._emphasis_stack_allocator_concept__emphasis_"><span class="emphasis"><em>stack-allocator
+        concept</em></span></a>
+      </h5>
+<p>
+        A <span class="emphasis"><em>StackAllocator</em></span> must satisfy the <span class="emphasis"><em>stack-allocator
+        concept</em></span> requirements shown in the following table, in which <code class="computeroutput"><span class="identifier">a</span></code> is an object of a <span class="emphasis"><em>StackAllocator</em></span>
+        type, <code class="computeroutput"><span class="identifier">sctx</span></code> is a <code class="computeroutput"><span class="identifier">stack_context</span></code>, and <code class="computeroutput"><span class="identifier">size</span></code>
+        is a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span></code>:
+      </p>
+<div class="informaltable"><table class="table">
+<colgroup>
+<col>
+<col>
+<col>
+</colgroup>
+<thead><tr>
+<th>
+                <p>
+                  expression
+                </p>
+              </th>
+<th>
+                <p>
+                  return type
+                </p>
+              </th>
+<th>
+                <p>
+                  notes
+                </p>
+              </th>
+</tr></thead>
+<tbody>
+<tr>
+<td>
+                <p>
+                  <code class="computeroutput"><span class="identifier">a</span><span class="special">(</span><span class="identifier">size</span><span class="special">)</span></code>
+                </p>
+              </td>
+<td>
+              </td>
+<td>
+                <p>
+                  creates a stack allocator
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">allocate</span><span class="special">()</span></code>
+                </p>
+              </td>
+<td>
+                <p>
+                  <code class="computeroutput"><span class="identifier">stack_context</span></code>
+                </p>
+              </td>
+<td>
+                <p>
+                  creates a stack
+                </p>
+              </td>
+</tr>
+<tr>
+<td>
+                <p>
+                  <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">deallocate</span><span class="special">(</span>
+                  <span class="identifier">sctx</span><span class="special">)</span></code>
+                </p>
+              </td>
+<td>
+                <p>
+                  <code class="computeroutput"><span class="keyword">void</span></code>
+                </p>
+              </td>
+<td>
+                <p>
+                  deallocates the stack created by <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">allocate</span><span class="special">()</span></code>
+                </p>
+              </td>
+</tr>
+</tbody>
+</table></div>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          The implementation of <code class="computeroutput"><span class="identifier">allocate</span><span class="special">()</span></code> might include logic to protect against
+          exceeding the context's available stack size rather than leaving it as
+          undefined behaviour.
+        </p></td></tr>
+</table></div>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          Calling <code class="computeroutput"><span class="identifier">deallocate</span><span class="special">()</span></code>
+          with a <code class="computeroutput"><span class="identifier">stack_context</span></code> not
+          set by <code class="computeroutput"><span class="identifier">allocate</span><span class="special">()</span></code>
+          results in undefined behaviour.
+        </p></td></tr>
+</table></div>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          The stack is not required to be aligned; alignment takes place inside
+          <span class="emphasis"><em>execution_context</em></span>.
+        </p></td></tr>
+</table></div>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          Depending on the architecture <code class="computeroutput"><span class="identifier">allocate</span><span class="special">()</span></code> stores an address from the top of the
+          stack (growing downwards) or the bottom of the stack (growing upwards).
+        </p></td></tr>
+</table></div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../econtext.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../econtext.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack/protected_fixedsize.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/stack/fixedsize.html b/libs/context/doc/html/context/econtext/stack/fixedsize.html
new file mode 100644
index 000000000..80bce593a
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/stack/fixedsize.html
@@ -0,0 +1,113 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class fixedsize</title>
+<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="protected_fixedsize.html" title="Class protected_fixedsize">
+<link rel="next" href="segmented.html" title="Class segmented">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="protected_fixedsize.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="segmented.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h4 class="title">
+<a name="context.econtext.stack.fixedsize"></a><a class="link" href="fixedsize.html" title="Class fixedsize">Class <span class="emphasis"><em>fixedsize</em></span></a>
+</h4></div></div></div>
+<p>
+          __boost_coroutine__ provides the class <span class="emphasis"><em>fixedsize</em></span> which
+          models the <span class="emphasis"><em>stack-allocator concept</em></span>. In contrast to
+          <span class="emphasis"><em>protected_fixedsize</em></span> it does not append a guard page
+          at the end of each stack. The memory is simply managed by <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">malloc</span><span class="special">()</span></code>
+          and <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">free</span><span class="special">()</span></code>.
+        </p>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">fixedsize</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">traitsT</span> <span class="special">&gt;</span>
+<span class="keyword">struct</span> <span class="identifier">basic_fixedsize</span>
+<span class="special">{</span>
+    <span class="keyword">typedef</span> <span class="identifier">traitT</span>  <span class="identifier">traits_type</span><span class="special">;</span>
+
+    <span class="identifier">basic_fixesize</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">default_size</span><span class="special">());</span>
+
+    <span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">();</span>
+
+    <span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span> <span class="special">&amp;);</span>
+<span class="special">}</span>
+
+<span class="keyword">typedef</span> <span class="identifier">basic_fixedsize</span><span class="special">&lt;</span> <span class="identifier">stack_traits</span> <span class="special">&gt;</span> <span class="identifier">fixedsize</span>
+</pre>
+<h6>
+<a name="context.econtext.stack.fixedsize.h0"></a>
+          <span><a name="context.econtext.stack.fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="fixedsize.html#context.econtext.stack.fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+                <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+                <span class="special">&lt;=</span> <span class="identifier">size</span></code>
+                and <code class="computeroutput"><span class="special">!</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span> <span class="special">&amp;&amp;</span>
+                <span class="special">(</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&gt;=</span>
+                <span class="identifier">size</span><span class="special">)</span></code>.
+              </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+                Allocates memory of at least <code class="computeroutput"><span class="identifier">size</span></code>
+                Bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
+                (the stack grows downwards/upwards) the stored address is the highest/lowest
+                address of the stack.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.fixedsize.h1"></a>
+          <span><a name="context.econtext.stack.fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="fixedsize.html#context.econtext.stack.fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span>
+          <span class="special">&amp;</span> <span class="identifier">sctx</span><span class="special">)</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+                <code class="computeroutput"><span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span></code> is valid, <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&lt;=</span>
+                <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span></code> and <code class="computeroutput"><span class="special">!</span>
+                <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
+                <span class="special">&amp;&amp;</span> <span class="special">(</span>
+                <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+                <span class="special">&gt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span></code>.
+              </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+                Deallocates the stack space.
+              </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="protected_fixedsize.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="segmented.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/stack/protected_fixedsize.html b/libs/context/doc/html/context/econtext/stack/protected_fixedsize.html
new file mode 100644
index 000000000..80c5407b9
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+++ b/libs/context/doc/html/context/econtext/stack/protected_fixedsize.html
@@ -0,0 +1,136 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class protected_fixedsize</title>
+<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="../stack.html" title="Stack allocation">
+<link rel="next" href="fixedsize.html" title="Class fixedsize">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../stack.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="fixedsize.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h4 class="title">
+<a name="context.econtext.stack.protected_fixedsize"></a><a class="link" href="protected_fixedsize.html" title="Class protected_fixedsize">Class
+        <span class="emphasis"><em>protected_fixedsize</em></span></a>
+</h4></div></div></div>
+<p>
+          <span class="bold"><strong>Boost.Context</strong></span> provides the class <span class="emphasis"><em>protected_fixedsize</em></span>
+          which models the <span class="emphasis"><em>stack-allocator concept</em></span>. It appends
+          a guard page at the end of each stack to protect against exceeding the
+          stack. If the guard page is accessed (read or write operation) a segmentation
+          fault/access violation is generated by the operating system.
+        </p>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+            Using <span class="emphasis"><em>protected_fixedsize</em></span> is expensive. That is,
+            launching a new coroutine with a new stack is expensive; the allocated
+            stack is just as efficient to use as any other stack.
+          </p></td></tr>
+</table></div>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+            The appended <code class="computeroutput"><span class="identifier">guard</span> <span class="identifier">page</span></code>
+            is <span class="bold"><strong>not</strong></span> mapped to physical memory, only
+            virtual addresses are used.
+          </p></td></tr>
+</table></div>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">protected_fixedsize</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">traitsT</span> <span class="special">&gt;</span>
+<span class="keyword">struct</span> <span class="identifier">basic_protected_fixedsize</span>
+<span class="special">{</span>
+    <span class="keyword">typedef</span> <span class="identifier">traitT</span>  <span class="identifier">traits_type</span><span class="special">;</span>
+
+    <span class="identifier">basic_protected_fixesize</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">default_size</span><span class="special">());</span>
+
+    <span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">();</span>
+
+    <span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span> <span class="special">&amp;);</span>
+<span class="special">}</span>
+
+<span class="keyword">typedef</span> <span class="identifier">basic_protected_fixedsize</span><span class="special">&lt;</span> <span class="identifier">stack_traits</span> <span class="special">&gt;</span> <span class="identifier">protected_fixedsize</span>
+</pre>
+<h6>
+<a name="context.econtext.stack.protected_fixedsize.h0"></a>
+          <span><a name="context.econtext.stack.protected_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="protected_fixedsize.html#context.econtext.stack.protected_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+                <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+                <span class="special">&lt;=</span> <span class="identifier">size</span></code>
+                and <code class="computeroutput"><span class="special">!</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span> <span class="special">&amp;&amp;</span>
+                <span class="special">(</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&gt;=</span>
+                <span class="identifier">size</span><span class="special">)</span></code>.
+              </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+                Allocates memory of at least <code class="computeroutput"><span class="identifier">size</span></code>
+                Bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
+                (the stack grows downwards/upwards) the stored address is the highest/lowest
+                address of the stack.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.protected_fixedsize.h1"></a>
+          <span><a name="context.econtext.stack.protected_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="protected_fixedsize.html#context.econtext.stack.protected_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span>
+          <span class="special">&amp;</span> <span class="identifier">sctx</span><span class="special">)</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+                <code class="computeroutput"><span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span></code> is valid, <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&lt;=</span>
+                <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span></code> and <code class="computeroutput"><span class="special">!</span>
+                <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
+                <span class="special">&amp;&amp;</span> <span class="special">(</span>
+                <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+                <span class="special">&gt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span></code>.
+              </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+                Deallocates the stack space.
+              </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../stack.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="fixedsize.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/stack/segmented.html b/libs/context/doc/html/context/econtext/stack/segmented.html
new file mode 100644
index 000000000..4339720ee
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/stack/segmented.html
@@ -0,0 +1,129 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class segmented</title>
+<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="fixedsize.html" title="Class fixedsize">
+<link rel="next" href="stack_traits.html" title="Class stack_traits">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="fixedsize.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_traits.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h4 class="title">
+<a name="context.econtext.stack.segmented"></a><a class="link" href="segmented.html" title="Class segmented">Class <span class="emphasis"><em>segmented</em></span></a>
+</h4></div></div></div>
+<p>
+          <span class="bold"><strong>Boost.Context</strong></span> supports usage of a <span class="emphasis"><em>segmented</em></span>,
+          e. g. the size of the stack grows on demand. The coroutine is created with
+          a minimal stack size and will be increased as required. Class <span class="emphasis"><em>segmented</em></span>
+          models the <span class="emphasis"><em>stack-allocator concept</em></span>. In contrast to
+          <span class="emphasis"><em>protected_fixedsize</em></span> and <span class="emphasis"><em>fixedsize</em></span>
+          it creates a stack which grows on demand.
+        </p>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+            Segmented stacks are currently only supported by <span class="bold"><strong>gcc</strong></span>
+            from version <span class="bold"><strong>4.7</strong></span> <span class="bold"><strong>clang</strong></span>
+            from version <span class="bold"><strong>3.4</strong></span> onwards. In order to
+            use a __segmented_stack__ <span class="bold"><strong>Boost.Context</strong></span>
+            must be built with <span class="bold"><strong>toolset=gcc segmented-stacks=on</strong></span>
+            at b2/bjam command-line. Applications must be compiled with compiler-flags
+            <span class="bold"><strong>-fsplit-stack -DBOOST_USE_SEGMENTED_STACKS</strong></span>.
+          </p></td></tr>
+</table></div>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">segmented</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">traitsT</span> <span class="special">&gt;</span>
+<span class="keyword">struct</span> <span class="identifier">basic_segmented</span>
+<span class="special">{</span>
+    <span class="keyword">typedef</span> <span class="identifier">traitT</span>  <span class="identifier">traits_type</span><span class="special">;</span>
+
+    <span class="identifier">basic_segmented</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">default_size</span><span class="special">());</span>
+
+    <span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">();</span>
+
+    <span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span> <span class="special">&amp;);</span>
+<span class="special">}</span>
+
+<span class="keyword">typedef</span> <span class="identifier">basic_segmented</span><span class="special">&lt;</span> <span class="identifier">stack_traits</span> <span class="special">&gt;</span> <span class="identifier">segmented</span><span class="special">;</span>
+</pre>
+<h6>
+<a name="context.econtext.stack.segmented.h0"></a>
+          <span><a name="context.econtext.stack.segmented._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="segmented.html#context.econtext.stack.segmented._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+                <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+                <span class="special">&lt;=</span> <span class="identifier">size</span></code>
+                and <code class="computeroutput"><span class="special">!</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span> <span class="special">&amp;&amp;</span>
+                <span class="special">(</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&gt;=</span>
+                <span class="identifier">size</span><span class="special">)</span></code>.
+              </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+                Allocates memory of at least <code class="computeroutput"><span class="identifier">size</span></code>
+                Bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
+                (the stack grows downwards/upwards) the stored address is the highest/lowest
+                address of the stack.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.segmented.h1"></a>
+          <span><a name="context.econtext.stack.segmented._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="segmented.html#context.econtext.stack.segmented._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span>
+          <span class="special">&amp;</span> <span class="identifier">sctx</span><span class="special">)</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+                <code class="computeroutput"><span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span></code> is valid, <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&lt;=</span>
+                <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span></code> and <code class="computeroutput"><span class="special">!</span>
+                <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
+                <span class="special">&amp;&amp;</span> <span class="special">(</span>
+                <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+                <span class="special">&gt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span></code>.
+              </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+                Deallocates the stack space.
+              </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="fixedsize.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_traits.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/stack/stack_context.html b/libs/context/doc/html/context/econtext/stack/stack_context.html
new file mode 100644
index 000000000..ea84c026d
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/stack/stack_context.html
@@ -0,0 +1,84 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class stack_context</title>
+<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="stack_traits.html" title="Class stack_traits">
+<link rel="next" href="../../performance.html" title="Performance">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack_traits.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../performance.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h4 class="title">
+<a name="context.econtext.stack.stack_context"></a><a class="link" href="stack_context.html" title="Class stack_context">Class <span class="emphasis"><em>stack_context</em></span></a>
+</h4></div></div></div>
+<p>
+          <span class="bold"><strong>Boost.Context</strong></span> provides the class <span class="emphasis"><em>stack_context</em></span>
+          which will contain the stack pointer and the size of the stack. In case
+          of a <span class="emphasis"><em>segmented</em></span>, <span class="emphasis"><em>stack_context</em></span>
+          contains some extra control structures.
+        </p>
+<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">stack_context</span>
+<span class="special">{</span>
+    <span class="keyword">void</span>    <span class="special">*</span>   <span class="identifier">sp</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">;</span>
+
+    <span class="comment">// might contain additional control structures</span>
+    <span class="comment">// for instance for segmented stacks</span>
+<span class="special">}</span>
+</pre>
+<h6>
+<a name="context.econtext.stack.stack_context.h0"></a>
+          <span><a name="context.econtext.stack.stack_context._code__phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase___code_"></a></span><a class="link" href="stack_context.html#context.econtext.stack.stack_context._code__phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="special">*</span> <span class="identifier">sp</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Value:</span></dt>
+<dd><p>
+                Pointer to the beginning of the stack.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.stack_context.h1"></a>
+          <span><a name="context.econtext.stack.stack_context._code__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase___code_"></a></span><a class="link" href="stack_context.html#context.econtext.stack.stack_context._code__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase___code_"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Value:</span></dt>
+<dd><p>
+                Actual size of the stack.
+              </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack_traits.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../performance.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/econtext/stack/stack_traits.html b/libs/context/doc/html/context/econtext/stack/stack_traits.html
new file mode 100644
index 000000000..88e48009b
--- /dev/null
+++ b/libs/context/doc/html/context/econtext/stack/stack_traits.html
@@ -0,0 +1,158 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class stack_traits</title>
+<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
+<link rel="home" href="../../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="segmented.html" title="Class segmented">
+<link rel="next" href="stack_context.html" title="Class stack_context">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="segmented.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_context.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h4 class="title">
+<a name="context.econtext.stack.stack_traits"></a><a class="link" href="stack_traits.html" title="Class stack_traits">Class <span class="emphasis"><em>stack_traits</em></span></a>
+</h4></div></div></div>
+<p>
+          <span class="emphasis"><em>stack_traits</em></span> models a <span class="emphasis"><em>stack-traits</em></span>
+          providing a way to access certain properites defined by the enironment.
+          Stack allocators use <span class="emphasis"><em>stack-traits</em></span> to allocate stacks.
+        </p>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">stack_traits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">struct</span> <span class="identifier">stack_traits</span>
+<span class="special">{</span>
+    <span class="keyword">static</span> <span class="keyword">bool</span> <span class="identifier">is_unbounded</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">page_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">default_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">minimum_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">maximum_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+<span class="special">}</span>
+</pre>
+<h6>
+<a name="context.econtext.stack.stack_traits.h0"></a>
+          <span><a name="context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__keyword__bool__phrase___phrase_role__identifier__is_unbounded__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__keyword__bool__phrase___phrase_role__identifier__is_unbounded__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="keyword">bool</span> <span class="identifier">is_unbounded</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+                Returns <code class="computeroutput"><span class="keyword">true</span></code> if the
+                environment defines no limit for the size of a stack.
+              </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+                Nothing.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.stack_traits.h1"></a>
+          <span><a name="context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__page_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__page_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">page_size</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+                Returns the page size in bytes.
+              </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+                Nothing.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.stack_traits.h2"></a>
+          <span><a name="context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__default_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__default_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">default_size</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+                Returns a default stack size, which may be platform specific. If
+                the stack is unbounded then the present implementation returns the
+                maximum of <code class="computeroutput"><span class="number">64</span> <span class="identifier">kB</span></code>
+                and <code class="computeroutput"><span class="identifier">minimum_size</span><span class="special">()</span></code>.
+              </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+                Nothing.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.stack_traits.h3"></a>
+          <span><a name="context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__minimum_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__minimum_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">minimum_size</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+                Returns the minimum size in bytes of stack defined by the environment
+                (Win32 4kB/Win64 8kB, defined by rlimit on POSIX).
+              </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+                Nothing.
+              </p></dd>
+</dl>
+</div>
+<h6>
+<a name="context.econtext.stack.stack_traits.h4"></a>
+          <span><a name="context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__maximum_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.econtext.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__maximum_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">maximum_size</span><span class="special">()</span></code></a>
+        </h6>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl>
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+                <code class="computeroutput"><span class="identifier">is_unbounded</span><span class="special">()</span></code>
+                returns <code class="computeroutput"><span class="keyword">false</span></code>.
+              </p></dd>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+                Returns the maximum size in bytes of stack defined by the environment.
+              </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+                Nothing.
+              </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="segmented.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_context.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/overview.html b/libs/context/doc/html/context/overview.html
index 7080161b6..e67770020 100644
--- a/libs/context/doc/html/context/overview.html
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 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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@@ -6,7 +6,7 @@
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 <link rel="up" href="../index.html" title="Chapter&#160;1.&#160;Context">
-<link rel="prev" href="context/boost_fcontext.html" title="fcontext_t and related functions">
+<link rel="prev" href="stack/valgrind.html" title="Support for valgrind">
 <link rel="next" href="architectures.html" title="Architectures">
 </head>
 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
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 </tr></table>
 <hr>
 <div class="spirit-nav">
-<a accesskey="p" href="context/boost_fcontext.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="architectures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+<a accesskey="p" href="stack/valgrind.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="architectures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
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 <div class="section">
 <div class="titlepage"><div><div><h2 class="title" style="clear: both">
@@ -125,7 +125,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>
@@ -133,7 +133,7 @@
 </tr></table>
 <hr>
 <div class="spirit-nav">
-<a accesskey="p" href="context/boost_fcontext.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="architectures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+<a accesskey="p" href="stack/valgrind.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="architectures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
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diff --git a/libs/context/doc/html/context/rationale.html b/libs/context/doc/html/context/rationale.html
index 8c8b6338d..23144d7d7 100644
--- a/libs/context/doc/html/context/rationale.html
+++ b/libs/context/doc/html/context/rationale.html
@@ -72,7 +72,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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diff --git a/libs/context/doc/html/context/rationale/other_apis_.html b/libs/context/doc/html/context/rationale/other_apis_.html
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--- a/libs/context/doc/html/context/rationale/other_apis_.html
+++ b/libs/context/doc/html/context/rationale/other_apis_.html
@@ -103,7 +103,7 @@
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 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>
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index c2b9fe3c5..49c2d0f2f 100644
--- a/libs/context/doc/html/context/rationale/x86_and_floating_point_env.html
+++ b/libs/context/doc/html/context/rationale/x86_and_floating_point_env.html
@@ -110,7 +110,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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diff --git a/libs/context/doc/html/context/reference.html b/libs/context/doc/html/context/reference.html
index b2877c2db..a4a18b319 100644
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@@ -90,7 +90,7 @@
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 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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index 27ccae0f3..beb8704da 100644
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+++ b/libs/context/doc/html/context/requirements.html
@@ -7,7 +7,7 @@
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 <link rel="prev" href="overview.html" title="Overview">
-<link rel="next" href="context.html" title="Context">
+<link rel="next" href="context.html" title="Struct fcontext_t">
 </head>
 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
 <table cellpadding="2" width="100%"><tr>
@@ -67,7 +67,7 @@
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 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2009 Oliver Kowalke<p>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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diff --git a/libs/context/doc/html/context/stack.html b/libs/context/doc/html/context/stack.html
new file mode 100644
index 000000000..699c984c3
--- /dev/null
+++ b/libs/context/doc/html/context/stack.html
@@ -0,0 +1,183 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Stack allocation</title>
+<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="prev" href="econtext.html" title="Class execution_context">
+<link rel="next" href="stack/protected_fixedsize.html" title="Class protected_fixedsize">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="econtext.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack/protected_fixedsize.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h2 class="title" style="clear: both">
+<a name="context.stack"></a><a class="link" href="stack.html" title="Stack allocation">Stack allocation</a>
+</h2></div></div></div>
+<div class="toc"><dl class="toc">
+<dt><span class="section"><a href="stack/protected_fixedsize.html">Class <span class="emphasis"><em>protected_fixedsize</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/fixedsize.html">Class <span class="emphasis"><em>fixedsize_stack</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/segmented.html">Class <span class="emphasis"><em>segmented_stack</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/stack_traits.html">Class <span class="emphasis"><em>stack_traits</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/stack_context.html">Class <span class="emphasis"><em>stack_context</em></span></a></span></dt>
+<dt><span class="section"><a href="stack/valgrind.html">Support for valgrind</a></span></dt>
+</dl></div>
+<p>
+      The memory used by the stack is allocated/deallocated via a <span class="emphasis"><em>StackAllocator</em></span>
+      which is required to model a <span class="emphasis"><em>stack-allocator concept</em></span>.
+    </p>
+<h4>
+<a name="context.stack.h0"></a>
+      <span class="phrase"><a name="context.stack._emphasis_stack_allocator_concept__emphasis_"></a></span><a class="link" href="stack.html#context.stack._emphasis_stack_allocator_concept__emphasis_"><span class="emphasis"><em>stack-allocator
+      concept</em></span></a>
+    </h4>
+<p>
+      A <span class="emphasis"><em>StackAllocator</em></span> must satisfy the <span class="emphasis"><em>stack-allocator
+      concept</em></span> requirements shown in the following table, in which <code class="computeroutput"><span class="identifier">a</span></code> is an object of a <span class="emphasis"><em>StackAllocator</em></span>
+      type, <code class="computeroutput"><span class="identifier">sctx</span></code> is a <code class="computeroutput"><span class="identifier">stack_context</span></code>, and <code class="computeroutput"><span class="identifier">size</span></code>
+      is a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span></code>:
+    </p>
+<div class="informaltable"><table class="table">
+<colgroup>
+<col>
+<col>
+<col>
+</colgroup>
+<thead><tr>
+<th>
+              <p>
+                expression
+              </p>
+            </th>
+<th>
+              <p>
+                return type
+              </p>
+            </th>
+<th>
+              <p>
+                notes
+              </p>
+            </th>
+</tr></thead>
+<tbody>
+<tr>
+<td>
+              <p>
+                <code class="computeroutput"><span class="identifier">a</span><span class="special">(</span><span class="identifier">size</span><span class="special">)</span></code>
+              </p>
+            </td>
+<td>
+            </td>
+<td>
+              <p>
+                creates a stack allocator
+              </p>
+            </td>
+</tr>
+<tr>
+<td>
+              <p>
+                <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">allocate</span><span class="special">()</span></code>
+              </p>
+            </td>
+<td>
+              <p>
+                <code class="computeroutput"><span class="identifier">stack_context</span></code>
+              </p>
+            </td>
+<td>
+              <p>
+                creates a stack
+              </p>
+            </td>
+</tr>
+<tr>
+<td>
+              <p>
+                <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">deallocate</span><span class="special">(</span>
+                <span class="identifier">sctx</span><span class="special">)</span></code>
+              </p>
+            </td>
+<td>
+              <p>
+                <code class="computeroutput"><span class="keyword">void</span></code>
+              </p>
+            </td>
+<td>
+              <p>
+                deallocates the stack created by <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">allocate</span><span class="special">()</span></code>
+              </p>
+            </td>
+</tr>
+</tbody>
+</table></div>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+        The implementation of <code class="computeroutput"><span class="identifier">allocate</span><span class="special">()</span></code> might include logic to protect against
+        exceeding the context's available stack size rather than leaving it as undefined
+        behaviour.
+      </p></td></tr>
+</table></div>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+        Calling <code class="computeroutput"><span class="identifier">deallocate</span><span class="special">()</span></code>
+        with a <code class="computeroutput"><span class="identifier">stack_context</span></code> not
+        set by <code class="computeroutput"><span class="identifier">allocate</span><span class="special">()</span></code>
+        results in undefined behaviour.
+      </p></td></tr>
+</table></div>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+        The stack is not required to be aligned; alignment takes place inside <span class="emphasis"><em>execution_context</em></span>.
+      </p></td></tr>
+</table></div>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+        Depending on the architecture <code class="computeroutput"><span class="identifier">allocate</span><span class="special">()</span></code> stores an address from the top of the stack
+        (growing downwards) or the bottom of the stack (growing upwards).
+      </p></td></tr>
+</table></div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="econtext.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack/protected_fixedsize.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/stack/fixedsize.html b/libs/context/doc/html/context/stack/fixedsize.html
new file mode 100644
index 000000000..f430c200a
--- /dev/null
+++ b/libs/context/doc/html/context/stack/fixedsize.html
@@ -0,0 +1,110 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class fixedsize_stack</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="protected_fixedsize.html" title="Class protected_fixedsize">
+<link rel="next" href="segmented.html" title="Class segmented_stack">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="protected_fixedsize.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="segmented.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.stack.fixedsize"></a><a class="link" href="fixedsize.html" title="Class fixedsize_stack">Class <span class="emphasis"><em>fixedsize_stack</em></span></a>
+</h3></div></div></div>
+<p>
+        <span class="bold"><strong>Boost.Context</strong></span> provides the class <span class="emphasis"><em>fixedsize_stack</em></span>
+        which models the <span class="emphasis"><em>stack-allocator concept</em></span>. In contrast
+        to <span class="emphasis"><em>protected_fixedsize_stack</em></span> it does not append a guard
+        page at the end of each stack. The memory is simply managed by <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">malloc</span><span class="special">()</span></code> and <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">free</span><span class="special">()</span></code>.
+      </p>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">fixedsize_stack</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">traitsT</span> <span class="special">&gt;</span>
+<span class="keyword">struct</span> <span class="identifier">basic_fixedsize_stack</span>
+<span class="special">{</span>
+    <span class="keyword">typedef</span> <span class="identifier">traitT</span>  <span class="identifier">traits_type</span><span class="special">;</span>
+
+    <span class="identifier">basic_fixesize_stack</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">default_size</span><span class="special">());</span>
+
+    <span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">();</span>
+
+    <span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span> <span class="special">&amp;);</span>
+<span class="special">}</span>
+
+<span class="keyword">typedef</span> <span class="identifier">basic_fixedsize_stack</span><span class="special">&lt;</span> <span class="identifier">stack_traits</span> <span class="special">&gt;</span> <span class="identifier">fixedsize_stack</span><span class="special">;</span>
+</pre>
+<h5>
+<a name="context.stack.fixedsize.h0"></a>
+        <span class="phrase"><a name="context.stack.fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="fixedsize.html#context.stack.fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+              <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+              <span class="special">&lt;=</span> <span class="identifier">size</span></code>
+              and <code class="computeroutput"><span class="special">!</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span> <span class="special">&amp;&amp;</span>
+              <span class="special">(</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&gt;=</span> <span class="identifier">size</span><span class="special">)</span></code>.
+            </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+              Allocates memory of at least <code class="computeroutput"><span class="identifier">size</span></code>
+              Bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
+              (the stack grows downwards/upwards) the stored address is the highest/lowest
+              address of the stack.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.fixedsize.h1"></a>
+        <span class="phrase"><a name="context.stack.fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="fixedsize.html#context.stack.fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span>
+        <span class="special">&amp;</span> <span class="identifier">sctx</span><span class="special">)</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+              <code class="computeroutput"><span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span></code> is valid, <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&lt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span></code> and <code class="computeroutput"><span class="special">!</span>
+              <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
+              <span class="special">&amp;&amp;</span> <span class="special">(</span>
+              <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+              <span class="special">&gt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span></code>.
+            </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+              Deallocates the stack space.
+            </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="protected_fixedsize.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="segmented.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/stack/protected_fixedsize.html b/libs/context/doc/html/context/stack/protected_fixedsize.html
new file mode 100644
index 000000000..99da13e1f
--- /dev/null
+++ b/libs/context/doc/html/context/stack/protected_fixedsize.html
@@ -0,0 +1,133 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class protected_fixedsize</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="../stack.html" title="Stack allocation">
+<link rel="next" href="fixedsize.html" title="Class fixedsize_stack">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../stack.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="fixedsize.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.stack.protected_fixedsize"></a><a class="link" href="protected_fixedsize.html" title="Class protected_fixedsize">Class <span class="emphasis"><em>protected_fixedsize</em></span></a>
+</h3></div></div></div>
+<p>
+        <span class="bold"><strong>Boost.Context</strong></span> provides the class <span class="emphasis"><em>protected_fixedsize_stack</em></span>
+        which models the <span class="emphasis"><em>stack-allocator concept</em></span>. It appends
+        a guard page at the end of each stack to protect against exceeding the stack.
+        If the guard page is accessed (read or write operation) a segmentation fault/access
+        violation is generated by the operating system.
+      </p>
+<div class="important"><table border="0" summary="Important">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../../doc/src/images/important.png"></td>
+<th align="left">Important</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          Using <span class="emphasis"><em>protected_fixedsize_stack</em></span> is expensive. That
+          is, launching a new coroutine with a new stack is expensive; the allocated
+          stack is just as efficient to use as any other stack.
+        </p></td></tr>
+</table></div>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          The appended <code class="computeroutput"><span class="identifier">guard</span> <span class="identifier">page</span></code>
+          is <span class="bold"><strong>not</strong></span> mapped to physical memory, only
+          virtual addresses are used.
+        </p></td></tr>
+</table></div>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">protected_fixedsize</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">traitsT</span> <span class="special">&gt;</span>
+<span class="keyword">struct</span> <span class="identifier">basic_protected_fixedsize</span>
+<span class="special">{</span>
+    <span class="keyword">typedef</span> <span class="identifier">traitT</span>  <span class="identifier">traits_type</span><span class="special">;</span>
+
+    <span class="identifier">basic_protected_fixesize</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">default_size</span><span class="special">());</span>
+
+    <span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">();</span>
+
+    <span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span> <span class="special">&amp;);</span>
+<span class="special">}</span>
+
+<span class="keyword">typedef</span> <span class="identifier">basic_protected_fixedsize</span><span class="special">&lt;</span> <span class="identifier">stack_traits</span> <span class="special">&gt;</span> <span class="identifier">protected_fixedsize</span>
+</pre>
+<h5>
+<a name="context.stack.protected_fixedsize.h0"></a>
+        <span class="phrase"><a name="context.stack.protected_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="protected_fixedsize.html#context.stack.protected_fixedsize._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+              <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+              <span class="special">&lt;=</span> <span class="identifier">size</span></code>
+              and <code class="computeroutput"><span class="special">!</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span> <span class="special">&amp;&amp;</span>
+              <span class="special">(</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&gt;=</span> <span class="identifier">size</span><span class="special">)</span></code>.
+            </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+              Allocates memory of at least <code class="computeroutput"><span class="identifier">size</span></code>
+              Bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
+              (the stack grows downwards/upwards) the stored address is the highest/lowest
+              address of the stack.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.protected_fixedsize.h1"></a>
+        <span class="phrase"><a name="context.stack.protected_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="protected_fixedsize.html#context.stack.protected_fixedsize._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span>
+        <span class="special">&amp;</span> <span class="identifier">sctx</span><span class="special">)</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+              <code class="computeroutput"><span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span></code> is valid, <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&lt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span></code> and <code class="computeroutput"><span class="special">!</span>
+              <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
+              <span class="special">&amp;&amp;</span> <span class="special">(</span>
+              <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+              <span class="special">&gt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span></code>.
+            </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+              Deallocates the stack space.
+            </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="../stack.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="fixedsize.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/stack/segmented.html b/libs/context/doc/html/context/stack/segmented.html
new file mode 100644
index 000000000..71b973900
--- /dev/null
+++ b/libs/context/doc/html/context/stack/segmented.html
@@ -0,0 +1,127 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class segmented_stack</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="fixedsize.html" title="Class fixedsize_stack">
+<link rel="next" href="stack_traits.html" title="Class stack_traits">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="fixedsize.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_traits.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.stack.segmented"></a><a class="link" href="segmented.html" title="Class segmented_stack">Class <span class="emphasis"><em>segmented_stack</em></span></a>
+</h3></div></div></div>
+<p>
+        <span class="bold"><strong>Boost.Context</strong></span> supports usage of a <span class="emphasis"><em>segmented_stack</em></span>,
+        e. g. the size of the stack grows on demand. The coroutine is created with
+        a minimal stack size and will be increased as required. Class <span class="emphasis"><em>segmented_stack</em></span>
+        models the <span class="emphasis"><em>stack-allocator concept</em></span>. In contrast to
+        <span class="emphasis"><em>protected_fixedsize_stack</em></span> and <span class="emphasis"><em>fixedsize_stack</em></span>
+        it creates a stack which grows on demand.
+      </p>
+<div class="note"><table border="0" summary="Note">
+<tr>
+<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td>
+<th align="left">Note</th>
+</tr>
+<tr><td align="left" valign="top"><p>
+          Segmented stacks are currently only supported by <span class="bold"><strong>gcc</strong></span>
+          from version <span class="bold"><strong>4.7</strong></span> <span class="bold"><strong>clang</strong></span>
+          from version <span class="bold"><strong>3.4</strong></span> onwards. In order to
+          use a __segmented_stack__ <span class="bold"><strong>Boost.Context</strong></span>
+          must be built with <span class="bold"><strong>toolset=gcc segmented-stacks=on</strong></span>
+          at b2/bjam command-line. Applications must be compiled with compiler-flags
+          <span class="bold"><strong>-fsplit-stack -DBOOST_USE_SEGMENTED_STACKS</strong></span>.
+        </p></td></tr>
+</table></div>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">segmented_stack</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">traitsT</span> <span class="special">&gt;</span>
+<span class="keyword">struct</span> <span class="identifier">basic_segmented_stack</span>
+<span class="special">{</span>
+    <span class="keyword">typedef</span> <span class="identifier">traitT</span>  <span class="identifier">traits_type</span><span class="special">;</span>
+
+    <span class="identifier">basic_segmented_stack</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span> <span class="special">=</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">default_size</span><span class="special">());</span>
+
+    <span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">();</span>
+
+    <span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span> <span class="special">&amp;);</span>
+<span class="special">}</span>
+
+<span class="keyword">typedef</span> <span class="identifier">basic_segmented_stack</span><span class="special">&lt;</span> <span class="identifier">stack_traits</span> <span class="special">&gt;</span> <span class="identifier">segmented_stack</span><span class="special">;</span>
+</pre>
+<h5>
+<a name="context.stack.segmented.h0"></a>
+        <span class="phrase"><a name="context.stack.segmented._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="segmented.html#context.stack.segmented._code__phrase_role__identifier__stack_context__phrase___phrase_role__identifier__allocate__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="identifier">stack_context</span> <span class="identifier">allocate</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+              <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+              <span class="special">&lt;=</span> <span class="identifier">size</span></code>
+              and <code class="computeroutput"><span class="special">!</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span> <span class="special">&amp;&amp;</span>
+              <span class="special">(</span> <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&gt;=</span> <span class="identifier">size</span><span class="special">)</span></code>.
+            </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+              Allocates memory of at least <code class="computeroutput"><span class="identifier">size</span></code>
+              Bytes and stores a pointer to the stack and its actual size in <code class="computeroutput"><span class="identifier">sctx</span></code>. Depending on the architecture
+              (the stack grows downwards/upwards) the stored address is the highest/lowest
+              address of the stack.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.segmented.h1"></a>
+        <span class="phrase"><a name="context.stack.segmented._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"></a></span><a class="link" href="segmented.html#context.stack.segmented._code__phrase_role__keyword__void__phrase___phrase_role__identifier__deallocate__phrase__phrase_role__special_____phrase___phrase_role__identifier__stack_context__phrase___phrase_role__special___amp___phrase___phrase_role__identifier__sctx__phrase__phrase_role__special_____phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="identifier">deallocate</span><span class="special">(</span> <span class="identifier">stack_context</span>
+        <span class="special">&amp;</span> <span class="identifier">sctx</span><span class="special">)</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+              <code class="computeroutput"><span class="identifier">sctx</span><span class="special">.</span><span class="identifier">sp</span></code> is valid, <code class="computeroutput"><span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">minimum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span> <span class="special">&lt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span></code> and <code class="computeroutput"><span class="special">!</span>
+              <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">is_unbounded</span><span class="special">()</span>
+              <span class="special">&amp;&amp;</span> <span class="special">(</span>
+              <span class="identifier">traits_type</span><span class="special">::</span><span class="identifier">maximum</span><span class="special">:</span><span class="identifier">size</span><span class="special">()</span>
+              <span class="special">&gt;=</span> <span class="identifier">sctx</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span></code>.
+            </p></dd>
+<dt><span class="term">Effects:</span></dt>
+<dd><p>
+              Deallocates the stack space.
+            </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="fixedsize.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_traits.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/stack/stack_context.html b/libs/context/doc/html/context/stack/stack_context.html
new file mode 100644
index 000000000..9a4ad3861
--- /dev/null
+++ b/libs/context/doc/html/context/stack/stack_context.html
@@ -0,0 +1,85 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class stack_context</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="stack_traits.html" title="Class stack_traits">
+<link rel="next" href="valgrind.html" title="Support for valgrind">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack_traits.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="valgrind.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.stack.stack_context"></a><a class="link" href="stack_context.html" title="Class stack_context">Class <span class="emphasis"><em>stack_context</em></span></a>
+</h3></div></div></div>
+<p>
+        <span class="bold"><strong>Boost.Context</strong></span> provides the class <span class="emphasis"><em>stack_context</em></span>
+        which will contain the stack pointer and the size of the stack. In case of
+        a <span class="emphasis"><em>segmented_stack</em></span>, <span class="emphasis"><em>stack_context</em></span>
+        contains some extra control structures.
+      </p>
+<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">stack_context</span>
+<span class="special">{</span>
+    <span class="keyword">void</span>    <span class="special">*</span>   <span class="identifier">sp</span><span class="special">;</span>
+    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">;</span>
+
+    <span class="comment">// might contain additional control structures</span>
+    <span class="comment">// for segmented stacks</span>
+<span class="special">}</span>
+</pre>
+<h5>
+<a name="context.stack.stack_context.h0"></a>
+        <span class="phrase"><a name="context.stack.stack_context._code__phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase___code_"></a></span><a class="link" href="stack_context.html#context.stack.stack_context._code__phrase_role__keyword__void__phrase___phrase_role__special_____phrase___phrase_role__identifier__sp__phrase___code_"><code class="computeroutput"><span class="keyword">void</span> <span class="special">*</span> <span class="identifier">sp</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Value:</span></dt>
+<dd><p>
+              Pointer to the beginning of the stack.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.stack_context.h1"></a>
+        <span class="phrase"><a name="context.stack.stack_context._code__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase___code_"></a></span><a class="link" href="stack_context.html#context.stack.stack_context._code__phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__size__phrase___code_"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span>
+        <span class="identifier">size</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Value:</span></dt>
+<dd><p>
+              Actual size of the stack.
+            </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack_traits.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="valgrind.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/stack/stack_traits.html b/libs/context/doc/html/context/stack/stack_traits.html
new file mode 100644
index 000000000..a15f5f1be
--- /dev/null
+++ b/libs/context/doc/html/context/stack/stack_traits.html
@@ -0,0 +1,158 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Class stack_traits</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="segmented.html" title="Class segmented_stack">
+<link rel="next" href="stack_context.html" title="Class stack_context">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="segmented.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_context.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.stack.stack_traits"></a><a class="link" href="stack_traits.html" title="Class stack_traits">Class <span class="emphasis"><em>stack_traits</em></span></a>
+</h3></div></div></div>
+<p>
+        <span class="emphasis"><em>stack_traits</em></span> models a <span class="emphasis"><em>stack-traits</em></span>
+        providing a way to access certain properites defined by the enironment. Stack
+        allocators use <span class="emphasis"><em>stack-traits</em></span> to allocate stacks.
+      </p>
+<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">context</span><span class="special">/</span><span class="identifier">stack_traits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
+
+<span class="keyword">struct</span> <span class="identifier">stack_traits</span>
+<span class="special">{</span>
+    <span class="keyword">static</span> <span class="keyword">bool</span> <span class="identifier">is_unbounded</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">page_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">default_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">minimum_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+
+    <span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">maximum_size</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span>
+<span class="special">}</span>
+</pre>
+<h5>
+<a name="context.stack.stack_traits.h0"></a>
+        <span class="phrase"><a name="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__keyword__bool__phrase___phrase_role__identifier__is_unbounded__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__keyword__bool__phrase___phrase_role__identifier__is_unbounded__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="keyword">bool</span> <span class="identifier">is_unbounded</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+              Returns <code class="computeroutput"><span class="keyword">true</span></code> if the environment
+              defines no limit for the size of a stack.
+            </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+              Nothing.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.stack_traits.h1"></a>
+        <span class="phrase"><a name="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__page_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__page_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">page_size</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+              Returns the page size in bytes.
+            </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+              Nothing.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.stack_traits.h2"></a>
+        <span class="phrase"><a name="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__default_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__default_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">default_size</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+              Returns a default stack size, which may be platform specific. If the
+              stack is unbounded then the present implementation returns the maximum
+              of <code class="computeroutput"><span class="number">64</span> <span class="identifier">kB</span></code>
+              and <code class="computeroutput"><span class="identifier">minimum_size</span><span class="special">()</span></code>.
+            </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+              Nothing.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.stack_traits.h3"></a>
+        <span class="phrase"><a name="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__minimum_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__minimum_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">minimum_size</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+              Returns the minimum size in bytes of stack defined by the environment
+              (Win32 4kB/Win64 8kB, defined by rlimit on POSIX).
+            </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+              Nothing.
+            </p></dd>
+</dl>
+</div>
+<h5>
+<a name="context.stack.stack_traits.h4"></a>
+        <span class="phrase"><a name="context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__maximum_size__phrase__phrase_role__special______phrase___code_"></a></span><a class="link" href="stack_traits.html#context.stack.stack_traits._code__phrase_role__keyword__static__phrase___phrase_role__identifier__std__phrase__phrase_role__special______phrase__phrase_role__identifier__size_t__phrase___phrase_role__identifier__maximum_size__phrase__phrase_role__special______phrase___code_"><code class="computeroutput"><span class="keyword">static</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">maximum_size</span><span class="special">()</span></code></a>
+      </h5>
+<div class="variablelist">
+<p class="title"><b></b></p>
+<dl class="variablelist">
+<dt><span class="term">Preconditions:</span></dt>
+<dd><p>
+              <code class="computeroutput"><span class="identifier">is_unbounded</span><span class="special">()</span></code>
+              returns <code class="computeroutput"><span class="keyword">false</span></code>.
+            </p></dd>
+<dt><span class="term">Returns:</span></dt>
+<dd><p>
+              Returns the maximum size in bytes of stack defined by the environment.
+            </p></dd>
+<dt><span class="term">Throws:</span></dt>
+<dd><p>
+              Nothing.
+            </p></dd>
+</dl>
+</div>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="segmented.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="stack_context.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context/stack/valgrind.html b/libs/context/doc/html/context/stack/valgrind.html
new file mode 100644
index 000000000..e33e66f49
--- /dev/null
+++ b/libs/context/doc/html/context/stack/valgrind.html
@@ -0,0 +1,48 @@
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<title>Support for valgrind</title>
+<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
+<link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Context">
+<link rel="up" href="../stack.html" title="Stack allocation">
+<link rel="prev" href="stack_context.html" title="Class stack_context">
+<link rel="next" href="../performance.html" title="Performance">
+</head>
+<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
+<table cellpadding="2" width="100%"><tr>
+<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
+<td align="center"><a href="../../../../../../index.html">Home</a></td>
+<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
+<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
+<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
+<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack_context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../performance.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+<div class="section">
+<div class="titlepage"><div><div><h3 class="title">
+<a name="context.stack.valgrind"></a><a class="link" href="valgrind.html" title="Support for valgrind">Support for valgrind</a>
+</h3></div></div></div>
+<p>
+        Running programs that switch stacks under valgrind causes problems. Property
+        (b2 command-line) <code class="computeroutput"><span class="identifier">valgrind</span><span class="special">=</span><span class="identifier">on</span></code> let
+        valgrind treat the memory regions as stack space which suppresses the errors.
+      </p>
+</div>
+<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
+<td align="left"></td>
+<td align="right"><div class="copyright-footer">Copyright &#169; 2014 Oliver Kowalke<p>
+        Distributed under the Boost Software License, Version 1.0. (See accompanying
+        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
+      </p>
+</div></td>
+</tr></table>
+<hr>
+<div class="spirit-nav">
+<a accesskey="p" href="stack_context.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../stack.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../performance.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
+</div>
+</body>
+</html>
diff --git a/libs/context/doc/html/context_HTML.manifest b/libs/context/doc/html/context_HTML.manifest
index 354d0d6cb..c1d815723 100644
--- a/libs/context/doc/html/context_HTML.manifest
+++ b/libs/context/doc/html/context_HTML.manifest
@@ -2,7 +2,14 @@ index.html
 context/overview.html
 context/requirements.html
 context/context.html
-context/context/boost_fcontext.html
+context/econtext.html
+context/stack.html
+context/stack/protected_fixedsize.html
+context/stack/fixedsize.html
+context/stack/segmented.html
+context/stack/stack_traits.html
+context/stack/stack_context.html
+context/stack/valgrind.html
 context/performance.html
 context/architectures.html
 context/rationale.html
diff --git a/libs/context/doc/html/index.html b/libs/context/doc/html/index.html
index e5fd35ba4..9efdf5967 100644
--- a/libs/context/doc/html/index.html
+++ b/libs/context/doc/html/index.html
@@ -25,7 +25,7 @@
 <div><div class="author"><h3 class="author">
 <span class="firstname">Oliver</span> <span class="surname">Kowalke</span>
 </h3></div></div>
-<div><p class="copyright">Copyright &#169; 2009 Oliver Kowalke</p></div>
+<div><p class="copyright">Copyright &#169; 2014 Oliver Kowalke</p></div>
 <div><div class="legalnotice">
 <a name="context.legal"></a><p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -38,9 +38,17 @@
 <dl class="toc">
 <dt><span class="section"><a href="context/overview.html">Overview</a></span></dt>
 <dt><span class="section"><a href="context/requirements.html">Requirements</a></span></dt>
-<dt><span class="section"><a href="context/context.html">Context</a></span></dt>
-<dd><dl><dt><span class="section"><a href="context/context/boost_fcontext.html"><code class="computeroutput"><span class="identifier">fcontext_t</span></code>
-      and related functions</a></span></dt></dl></dd>
+<dt><span class="section"><a href="context/context.html">Struct fcontext_t</a></span></dt>
+<dt><span class="section"><a href="context/econtext.html">Class execution_context</a></span></dt>
+<dt><span class="section"><a href="context/stack.html">Stack allocation</a></span></dt>
+<dd><dl>
+<dt><span class="section"><a href="context/stack/protected_fixedsize.html">Class <span class="emphasis"><em>protected_fixedsize</em></span></a></span></dt>
+<dt><span class="section"><a href="context/stack/fixedsize.html">Class <span class="emphasis"><em>fixedsize_stack</em></span></a></span></dt>
+<dt><span class="section"><a href="context/stack/segmented.html">Class <span class="emphasis"><em>segmented_stack</em></span></a></span></dt>
+<dt><span class="section"><a href="context/stack/stack_traits.html">Class <span class="emphasis"><em>stack_traits</em></span></a></span></dt>
+<dt><span class="section"><a href="context/stack/stack_context.html">Class <span class="emphasis"><em>stack_context</em></span></a></span></dt>
+<dt><span class="section"><a href="context/stack/valgrind.html">Support for valgrind</a></span></dt>
+</dl></dd>
 <dt><span class="section"><a href="context/performance.html">Performance</a></span></dt>
 <dt><span class="section"><a href="context/architectures.html">Architectures</a></span></dt>
 <dt><span class="section"><a href="context/rationale.html">Rationale</a></span></dt>
@@ -55,7 +63,7 @@
 </div>
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
-<td align="left"><p><small>Last revised: October 30, 2014 at 10:14:04 GMT</small></p></td>
+<td align="left"><p><small>Last revised: April 07, 2015 at 22:43:34 GMT</small></p></td>
 <td align="right"><div class="copyright-footer"></div></td>
 </tr></table>
 <hr>
diff --git a/libs/context/doc/overview.qbk b/libs/context/doc/overview.qbk
index 2db4aa841..e28104176 100644
--- a/libs/context/doc/overview.qbk
+++ b/libs/context/doc/overview.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
diff --git a/libs/context/doc/performance.qbk b/libs/context/doc/performance.qbk
index 83018130f..4ab1ee1b5 100644
--- a/libs/context/doc/performance.qbk
+++ b/libs/context/doc/performance.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
diff --git a/libs/context/doc/rationale.qbk b/libs/context/doc/rationale.qbk
index 966a7d4f5..a034f2ab4 100644
--- a/libs/context/doc/rationale.qbk
+++ b/libs/context/doc/rationale.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
diff --git a/libs/context/doc/reference.qbk b/libs/context/doc/reference.qbk
index d7ab1ddbd..8d498ce8a 100644
--- a/libs/context/doc/reference.qbk
+++ b/libs/context/doc/reference.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
diff --git a/libs/context/doc/requirements.qbk b/libs/context/doc/requirements.qbk
index 0621b2fcd..4c16ace19 100644
--- a/libs/context/doc/requirements.qbk
+++ b/libs/context/doc/requirements.qbk
@@ -1,5 +1,5 @@
 [/
-          Copyright Oliver Kowalke 2009.
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
diff --git a/libs/context/doc/stack.qbk b/libs/context/doc/stack.qbk
index 5d179a7c6..b0461716f 100644
--- a/libs/context/doc/stack.qbk
+++ b/libs/context/doc/stack.qbk
@@ -1,4 +1,5 @@
-[/ Copyright Oliver Kowalke 2009.
+[/
+          Copyright Oliver Kowalke 2014.
  Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
           http://www.boost.org/LICENSE_1_0.txt
@@ -6,20 +7,294 @@
 
 [section:stack Stack allocation]
 
-A __fcontext__ requires a stack which will be allocated/deallocated
-by a __stack_allocator__ (examples contain an implementation
-of [@boost:/libs/context/example/simple_stack_allocator.hpp
-simple_stack_allocator]).
+The memory used by the stack is allocated/deallocated via a __stack_allocator__
+which is required to model a __stack_allocator_concept__.
 
-[note The implementation of a __stack_allocator__ might include logic to protect
+
+[heading __stack_allocator_concept__]
+A __stack_allocator__ must satisfy the __stack_allocator_concept__ requirements
+shown in the following table, in which `a` is an object of a
+__stack_allocator__ type, `sctx` is a `stack_context`, and `size` is a `std::size_t`:
+
+[table
+    [[expression][return type][notes]]
+    [
+        [`a(size)`]
+        []
+        [creates a stack allocator]
+    ]
+    [
+        [`a.allocate()`]
+        [`stack_context`]
+        [creates a stack]
+    ]
+    [
+        [`a.deallocate( sctx)`]
+        [`void`]
+        [deallocates the stack created by `a.allocate()`]
+    ]
+]
+
+[important The implementation of `allocate()` might include logic to protect
 against exceeding the context's available stack size rather than leaving it as
 undefined behaviour.]
 
+[important Calling `deallocate()` with a `stack_context` not set by `allocate()`
+results in undefined behaviour.]
+
 [note The stack is not required to be aligned; alignment takes place inside
-__make_fcontext__.]
+__econtext__.]
 
-[note Depending on the architecture __stack_allocator__ returns an address from
-the top of the stack (grows downwards) or the bottom of the stack (grows
+[note Depending on the architecture `allocate()` stores an address from the
+top of the stack (growing downwards) or the bottom of the stack (growing
 upwards).]
 
+
+[section:protected_fixedsize Class ['protected_fixedsize]]
+
+__boost_context__ provides the class __protected_fixedsize__ which models
+the __stack_allocator_concept__.
+It appends a guard page at the end of each stack to protect against exceeding
+the stack. If the guard page is accessed (read or write operation) a
+segmentation fault/access violation is generated by the operating system.
+
+[important Using __protected_fixedsize__ is expensive. That is, launching a
+new coroutine with a new stack is expensive; the allocated stack is just as
+efficient to use as any other stack.]
+
+[note The appended `guard page` is [*not] mapped to physical memory, only
+virtual addresses are used.]
+
+        #include <boost/context/protected_fixedsize.hpp>
+
+        template< typename traitsT >
+        struct basic_protected_fixedsize
+        {
+            typedef traitT  traits_type;
+
+            basic_protected_fixesize(std::size_t size = traits_type::default_size());
+
+            stack_context allocate();
+
+            void deallocate( stack_context &);
+        }
+
+        typedef basic_protected_fixedsize< stack_traits > protected_fixedsize
+
+[heading `stack_context allocate()`]
+[variablelist
+[[Preconditions:] [`traits_type::minimum:size() <= size` and
+`! traits_type::is_unbounded() && ( traits_type::maximum:size() >= size)`.]]
+[[Effects:] [Allocates memory of at least `size` Bytes and stores a pointer
+to the stack and its actual size in `sctx`. Depending
+on the architecture (the stack grows downwards/upwards) the stored address is
+the highest/lowest address of the stack.]]
+]
+
+[heading `void deallocate( stack_context & sctx)`]
+[variablelist
+[[Preconditions:] [`sctx.sp` is valid, `traits_type::minimum:size() <= sctx.size` and
+`! traits_type::is_unbounded() && ( traits_type::maximum:size() >= sctx.size)`.]]
+[[Effects:] [Deallocates the stack space.]]
+]
+
+[endsect]
+
+
+[section:fixedsize Class ['fixedsize_stack]]
+
+__boost_context__ provides the class __fixedsize__ which models
+the __stack_allocator_concept__.
+In contrast to __protected_fixedsize__ it does not append a guard page at the
+end of each stack. The memory is simply managed by `std::malloc()` and
+`std::free()`.
+
+        #include <boost/context/fixedsize_stack.hpp>
+
+        template< typename traitsT >
+        struct basic_fixedsize_stack
+        {
+            typedef traitT  traits_type;
+
+            basic_fixesize_stack(std::size_t size = traits_type::default_size());
+
+            stack_context allocate();
+
+            void deallocate( stack_context &);
+        }
+
+        typedef basic_fixedsize_stack< stack_traits > fixedsize_stack;
+
+[heading `stack_context allocate()`]
+[variablelist
+[[Preconditions:] [`traits_type::minimum:size() <= size` and
+`! traits_type::is_unbounded() && ( traits_type::maximum:size() >= size)`.]]
+[[Effects:] [Allocates memory of at least `size` Bytes and stores a pointer to
+the stack and its actual size in `sctx`. Depending on the architecture (the
+stack grows downwards/upwards) the stored address is the highest/lowest
+address of the stack.]]
+]
+
+[heading `void deallocate( stack_context & sctx)`]
+[variablelist
+[[Preconditions:] [`sctx.sp` is valid, `traits_type::minimum:size() <= sctx.size` and
+`! traits_type::is_unbounded() && ( traits_type::maximum:size() >= sctx.size)`.]]
+[[Effects:] [Deallocates the stack space.]]
+]
+
+[endsect]
+
+
+[section:segmented Class ['segmented_stack]]
+
+__boost_context__ supports usage of a __segmented__, e. g. the size of
+the stack grows on demand. The coroutine is created with a minimal stack size
+and will be increased as required.
+Class __segmented__ models the __stack_allocator_concept__.
+In contrast to __protected_fixedsize__ and __fixedsize__ it creates a
+stack which grows on demand.
+
+[note Segmented stacks are currently only supported by [*gcc] from version
+[*4.7] [*clang] from version [*3.4] onwards. In order to use a
+__segmented_stack__ __boost_context__ must be built with
+[*toolset=gcc segmented-stacks=on] at b2/bjam command-line. Applications
+must be compiled with compiler-flags
+[*-fsplit-stack -DBOOST_USE_SEGMENTED_STACKS].]
+
+        #include <boost/context/segmented_stack.hpp>
+
+        template< typename traitsT >
+        struct basic_segmented_stack
+        {
+            typedef traitT  traits_type;
+
+            basic_segmented_stack(std::size_t size = traits_type::default_size());
+
+            stack_context allocate();
+
+            void deallocate( stack_context &);
+        }
+
+        typedef basic_segmented_stack< stack_traits > segmented_stack;
+
+[heading `stack_context allocate()`]
+[variablelist
+[[Preconditions:] [`traits_type::minimum:size() <= size` and
+`! traits_type::is_unbounded() && ( traits_type::maximum:size() >= size)`.]]
+[[Effects:] [Allocates memory of at least `size` Bytes and stores a pointer to
+the stack and its actual size in `sctx`. Depending on the architecture (the
+stack grows downwards/upwards) the stored address is the highest/lowest
+address of the stack.]]
+]
+
+[heading `void deallocate( stack_context & sctx)`]
+[variablelist
+[[Preconditions:] [`sctx.sp` is valid, `traits_type::minimum:size() <= sctx.size` and
+`! traits_type::is_unbounded() && ( traits_type::maximum:size() >= sctx.size)`.]]
+[[Effects:] [Deallocates the stack space.]]
+]
+
+[endsect]
+
+
+[section:stack_traits Class ['stack_traits]]
+
+['stack_traits] models a __stack_traits__ providing a way to access certain
+properites defined by the enironment. Stack allocators use __stack_traits__ to
+allocate stacks.
+
+        #include <boost/context/stack_traits.hpp>
+
+        struct stack_traits
+        {
+            static bool is_unbounded() noexcept;
+
+            static std::size_t page_size() noexcept;
+
+            static std::size_t default_size() noexcept;
+
+            static std::size_t minimum_size() noexcept;
+
+            static std::size_t maximum_size() noexcept;
+        }
+
+
+[heading `static bool is_unbounded()`]
+[variablelist
+[[Returns:] [Returns `true` if the environment defines no limit for the size of
+a stack.]]
+[[Throws:] [Nothing.]]
+]
+
+[heading `static std::size_t page_size()`]
+[variablelist
+[[Returns:] [Returns the page size in bytes.]]
+[[Throws:] [Nothing.]]
+]
+
+[heading `static std::size_t default_size()`]
+[variablelist
+[[Returns:] [Returns a default stack size, which may be platform specific.
+If the stack is unbounded then the present implementation returns the maximum of
+`64 kB` and `minimum_size()`.]]
+[[Throws:] [Nothing.]]
+]
+
+[heading `static std::size_t minimum_size()`]
+[variablelist
+[[Returns:] [Returns the minimum size in bytes of stack defined by the
+environment (Win32 4kB/Win64 8kB, defined by rlimit on POSIX).]]
+[[Throws:] [Nothing.]]
+]
+
+[heading `static std::size_t maximum_size()`]
+[variablelist
+[[Preconditions:] [`is_unbounded()` returns `false`.]]
+[[Returns:] [Returns the maximum size in bytes of stack defined by the
+environment.]]
+[[Throws:] [Nothing.]]
+]
+
+
+[endsect]
+
+
+[section:stack_context Class ['stack_context]]
+
+__boost_context__ provides the class __stack_context__ which will contain
+the stack pointer and the size of the stack.
+In case of a __segmented__, __stack_context__ contains some extra control
+structures.
+
+        struct stack_context
+        {
+            void    *   sp;
+            std::size_t size;
+
+            // might contain additional control structures
+            // for segmented stacks
+        }
+
+[heading `void * sp`]
+[variablelist
+[[Value:] [Pointer to the beginning of the stack.]]
+]
+
+[heading `std::size_t size`]
+[variablelist
+[[Value:] [Actual size of the stack.]]
+]
+
+[endsect]
+
+
+[section:valgrind Support for valgrind]
+
+Running programs that switch stacks under valgrind causes problems.
+Property (b2 command-line) `valgrind=on` let valgrind treat the memory regions
+as stack space which suppresses the errors.
+
+[endsect]
+
+
 [endsect]