2013-11-16 Edward Smith-Rowland <3dw4rd@verizon.net>

	Implement N3762 string_view: a non-owning reference to a string.
	* include/Makefile.am: Add string_view and string_view.tcc.
	* include/Makefile.in: Regenerate.
	* include/experimental/string_view: Implement basic_string_view.
	* include/experimental/string_view.tcc: Implement basic_string_view.
	* testsuite/experimental/string_view/capacity/1.cc: New.
	* testsuite/experimental/string_view/cons/char/1.cc: New.
	* testsuite/experimental/string_view/cons/char/2.cc: New.
	* testsuite/experimental/string_view/cons/char/3.cc: New.
	* testsuite/experimental/string_view/cons/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/cons/wchar_t/2.cc: New.
	* testsuite/experimental/string_view/cons/wchar_t/3.cc: New.
	* testsuite/experimental/string_view/element_access/char/1.cc: New.
	* testsuite/experimental/string_view/element_access/char/2.cc: New.
	* testsuite/experimental/string_view/element_access/char/empty.cc: New.
	* testsuite/experimental/string_view/element_access/char/front_back.cc:
	New.
	* testsuite/experimental/string_view/element_access/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/element_access/wchar_t/2.cc: New.
	* testsuite/experimental/string_view/element_access/wchar_t/empty.cc:
	New.
	* testsuite/experimental/string_view/element_access/wchar_t/
	front_back.cc: New.
	* testsuite/experimental/string_view/include.cc: New.
	* testsuite/experimental/string_view/inserters/char/1.cc: New.
	* testsuite/experimental/string_view/inserters/char/2.cc: New.
	* testsuite/experimental/string_view/inserters/char/3.cc: New.
	* testsuite/experimental/string_view/inserters/pod/10081-out.cc: New.
	* testsuite/experimental/string_view/inserters/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/inserters/wchar_t/2.cc: New.
	* testsuite/experimental/string_view/inserters/wchar_t/3.cc: New.
	* testsuite/experimental/string_view/literals/types.cc: New.
	* testsuite/experimental/string_view/literals/values.cc: New.
	* testsuite/experimental/string_view/modifiers/remove_prefix/char/1.cc:
	New.
	* testsuite/experimental/string_view/modifiers/remove_prefix/wchar_t/
	1.cc: New.
	* testsuite/experimental/string_view/modifiers/remove_suffix/char/1.cc:
	New.
	* testsuite/experimental/string_view/modifiers/remove_suffix/wchar_t/
	1.cc: New.
	* testsuite/experimental/string_view/operations/compare/char/1.cc: New.
	* testsuite/experimental/string_view/operations/compare/char/13650.cc:
	New.
	* testsuite/experimental/string_view/operations/compare/wchar_t/1.cc:
	New.
	* testsuite/experimental/string_view/operations/compare/wchar_t/
	13650.cc: New.
	* testsuite/experimental/string_view/operations/data/char/1.cc: New.
	* testsuite/experimental/string_view/operations/data/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/operations/find/char/1.cc: New.
	* testsuite/experimental/string_view/operations/find/char/2.cc: New.
	* testsuite/experimental/string_view/operations/find/char/3.cc: New.
	* testsuite/experimental/string_view/operations/find/char/4.cc: New.
	* testsuite/experimental/string_view/operations/find/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/operations/find/wchar_t/2.cc: New.
	* testsuite/experimental/string_view/operations/find/wchar_t/3.cc: New.
	* testsuite/experimental/string_view/operations/find/wchar_t/4.cc: New.
	* testsuite/experimental/string_view/operations/rfind/char/1.cc: New.
	* testsuite/experimental/string_view/operations/rfind/char/2.cc: New.
	* testsuite/experimental/string_view/operations/rfind/char/3.cc: New.
	* testsuite/experimental/string_view/operations/rfind/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/operations/rfind/wchar_t/2.cc: New.
	* testsuite/experimental/string_view/operations/rfind/wchar_t/3.cc: New.
	* testsuite/experimental/string_view/operations/substr/char/1.cc: New.
	* testsuite/experimental/string_view/operations/substr/wchar_t/1.cc:
	New.
	* testsuite/experimental/string_view/operators/char/2.cc: New.
	* testsuite/experimental/string_view/operators/wchar_t/2.cc: New.
	* testsuite/experimental/string_view/range_access/char/1.cc: New.
	* testsuite/experimental/string_view/range_access/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/requirements/
	explicit_instantiation/1.cc: New.
	* testsuite/experimental/string_view/requirements/
	explicit_instantiation/char/1.cc: New.
	* testsuite/experimental/string_view/requirements/
	explicit_instantiation/char16_t/1.cc: New.
	* testsuite/experimental/string_view/requirements/
	explicit_instantiation/char32_t/1.cc: New.
	* testsuite/experimental/string_view/requirements/
	explicit_instantiation/wchar_t/1.cc: New.
	* testsuite/experimental/string_view/requirements/typedefs.cc: New.
	* testsuite/experimental/string_view/types/1.cc: New.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@204902 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 927 insertions, 0 deletions

diff --git a/libstdc++-v3/include/experimental/string_view b/libstdc++-v3/include/experimental/string_view
new file mode 100644
index 00000000000..d2cb7cfbb66
--- /dev/null
+++ b/libstdc++-v3/include/experimental/string_view
@@ -0,0 +1,697 @@
+// Components for manipulating non-owning sequences of characters -*- C++ -*-
+
+// Copyright (C) 2013 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file experimental/string_view
+ *  This is a Standard C++ Library header.
+ */
+
+//
+// ISO C++ 14882: 21  Strings library
+//
+
+#ifndef _GLIBCXX_EXPERIMENTAL_STRING_VIEW
+#define _GLIBCXX_EXPERIMENTAL_STRING_VIEW 1
+
+#pragma GCC system_header
+
+#if __cplusplus <= 201103L
+# include <bits/c++14_warning.h>
+#else
+
+#include <debug/debug.h>
+#include <string>
+#include <limits>
+
+namespace std //_GLIBCXX_VISIBILITY(default)
+{
+namespace experimental
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+  /**
+   *  @class basic_string_view <string_view>
+   *  @brief  A non-owning reference to a string.
+   *
+   *  @ingroup strings
+   *  @ingroup sequences
+   *
+   *  @tparam _CharT  Type of character
+   *  @tparam _Traits  Traits for character type, defaults to
+   *                   char_traits<_CharT>.
+   *
+   *  A basic_string_view looks like this:
+   *
+   *  @code
+   *    _CharT*    _M_str
+   *    size_t     _M_len
+   *  @endcode
+   */
+  template<typename _CharT, typename _Traits = char_traits<_CharT>>
+    class basic_string_view
+    {
+
+    public:
+
+      // types
+      using traits_type = _Traits;
+      using value_type = _CharT;
+      using pointer = const _CharT*;
+      using const_pointer = const _CharT*;
+      using reference = const _CharT&;
+      using const_reference = const _CharT&;
+      using const_iterator = const _CharT*;
+      using iterator = const_iterator;
+      using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+      using reverse_iterator = const_reverse_iterator;
+      using size_type = size_t;
+      using difference_type = ptrdiff_t;
+      static constexpr size_type npos = size_type(-1);
+
+      // [string.view.cons], construct/copy
+
+      constexpr
+      basic_string_view() noexcept
+      : _M_len{0}, _M_str{nullptr}
+      { }
+
+      constexpr basic_string_view(const basic_string_view&) noexcept = default;
+
+      template<typename _Allocator>
+        basic_string_view(const basic_string<_CharT, _Traits, _Allocator>& __str) noexcept
+        : _M_len{__str.length()}, _M_str{__str.data()}
+        { }
+
+      constexpr basic_string_view(const _CharT* __str)
+      : _M_len{__str == nullptr ? 0 : traits_type::length(__str)}, _M_str{__str}
+      { }
+
+      constexpr basic_string_view(const _CharT* __str, size_type __len)
+      : _M_len{__len}, _M_str{__str}
+      { }
+
+      basic_string_view&
+      operator=(const basic_string_view&) noexcept = default;
+
+      // [string.view.iterators], iterators
+
+      constexpr const_iterator
+      begin() const noexcept
+      { return this->_M_str; }
+
+      constexpr const_iterator
+      end() const noexcept
+      { return this->_M_str + this->_M_len; }
+
+      constexpr const_iterator
+      cbegin() const noexcept
+      { return this->_M_str; }
+
+      constexpr const_iterator
+      cend() const noexcept
+      { return this->_M_str + this->_M_len; }
+
+      const_reverse_iterator
+      rbegin() const noexcept
+      { return std::reverse_iterator<const_iterator>(this->end()); }
+
+      const_reverse_iterator
+      rend() const noexcept
+      { return std::reverse_iterator<const_iterator>(this->begin()); }
+
+      const_reverse_iterator
+      crbegin() const noexcept
+      { return std::reverse_iterator<const_iterator>(this->end()); }
+
+      const_reverse_iterator
+      crend() const noexcept
+      { return std::reverse_iterator<const_iterator>(this->begin()); }
+
+      // [string.view.capacity], capacity
+
+      constexpr size_type
+      size() const noexcept
+      { return this->_M_len; }
+
+      constexpr size_type
+      length() const noexcept
+      { return _M_len; }
+
+      constexpr size_type
+      max_size() const noexcept
+      { return _S_max_size; }
+
+      constexpr bool
+      empty() const noexcept
+      { return this->_M_len == 0; }
+
+      // [string.view.access], element access
+
+      constexpr const _CharT&
+      operator[](size_type __pos) const
+      {
+	_GLIBCXX_DEBUG_ASSERT(__pos <= this->_M_len);
+	return *(this->_M_str + __pos);
+      }
+
+      constexpr const _CharT&
+      at(size_type __pos) const
+      {
+	return __pos < this->_M_len
+	     ? *(this->_M_str + __pos)
+	     : (__throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
+					     "(which is %zu) >= this->size() "
+					     "(which is %zu)"),
+					 __pos, this->size()),
+		*static_cast<pointer>(nullptr));
+      }
+
+      constexpr const _CharT&
+      front() const
+      {
+	_GLIBCXX_DEBUG_ASSERT(this->_M_len > 0);
+	return *this->_M_str;
+      }
+
+      constexpr const _CharT&
+      back() const
+      {
+	_GLIBCXX_DEBUG_ASSERT(this->_M_len > 0);
+	return *(this->_M_str + this->_M_len - 1);
+      }
+
+      constexpr const _CharT*
+      data() const noexcept
+      { return this->_M_str; }
+
+      // [string.view.modifiers], modifiers:
+      void
+      clear() noexcept
+      {
+	this->_M_len = 0;
+	this->_M_str = nullptr;
+      }
+
+      void
+      remove_prefix(size_type __n)
+      {
+	_GLIBCXX_DEBUG_ASSERT(this->_M_len >= __n);
+	this->_M_str += __n;
+	this->_M_len -= __n;
+      }
+
+      void
+      remove_suffix(size_type __n)
+      { this->_M_len -= __n; }
+
+      void
+      swap(basic_string_view& __sv) noexcept
+      {
+	std::swap(this->_M_len, __sv._M_len);
+	std::swap(this->_M_str, __sv._M_str);
+      }
+
+
+      // [string.view.ops], string operations:
+
+      template<typename _Allocator>
+        explicit operator basic_string<_CharT, _Traits, _Allocator>() const
+        {
+	  return basic_string<_CharT, _Traits, _Allocator>
+					(this->_M_len, this->_M_str);
+	}
+
+      size_type
+      copy(_CharT* __str, size_type __n, size_type __pos = 0) const
+      {
+	__glibcxx_requires_string_len(__str, __n);
+	if (__pos >= this->_M_len)
+	  __throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
+				       "(which is %zu) >= this->size() "
+				       "(which is %zu)"),
+				   __pos, this->size());
+	size_type __rlen{std::min(__n, size_type{this->_M_len  - __pos})};
+	for (auto __begin = this->_M_str + __pos,
+	     __end = this->_M_str + __rlen; __begin != __end;)
+	  *__str++ = *__begin++;
+	return __rlen;
+      }
+
+
+      // [string.view.ops], string operations:
+
+      constexpr basic_string_view
+      substr(size_type __pos, size_type __n=npos) const
+      {
+	return __pos < this->_M_len
+	     ? basic_string_view{this->_M_str + __pos,
+				std::min(__n, size_type{this->_M_len  - __pos})}
+	     : (__throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
+					     "(which is %zu) >= this->size() "
+					     "(which is %zu)"),
+				     __pos, this->size()), basic_string_view{});
+      }
+
+      int
+      compare(basic_string_view __str) const noexcept
+      {
+	int __ret = traits_type::compare(this->_M_str, __str._M_str,
+					 std::min(this->_M_len, __str._M_len));
+	if (__ret == 0)
+	  __ret = _S_compare(this->_M_len, __str._M_len);
+	return __ret;
+      }
+
+      int
+      compare(size_type __pos1, size_type __n1, basic_string_view __str) const
+      { return this->substr(__pos1, __n1).compare(__str); }
+
+      int
+      compare(size_type __pos1, size_type __n1,
+	      basic_string_view __str, size_type __pos2, size_type __n2) const
+      { return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2)); }
+
+      int
+      compare(const _CharT* __str) const noexcept
+      { return this->compare(basic_string_view{__str}); }
+
+      int
+      compare(size_type __pos1, size_type __n1, const _CharT* __str) const
+      { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
+
+      int
+      compare(size_type __pos1, size_type __n1,
+	      const _CharT* __str, size_type __n2) const
+      {
+	return this->substr(__pos1, __n1)
+		   .compare(basic_string_view(__str, __n2));
+      }
+
+      size_type
+      find(basic_string_view __str, size_type __pos = 0) const noexcept
+      { return this->find(__str._M_str, __pos, __str._M_len); }
+
+      size_type
+      find(_CharT __c, size_type __pos=0) const noexcept;
+
+      size_type
+      find(const _CharT* __str, size_type __pos, size_type __n) const;
+
+      size_type
+      find(const _CharT* __str, size_type __pos=0) const noexcept
+      { return this->find(__str, __pos, traits_type::length(__str)); }
+
+      size_type
+      rfind(basic_string_view __str, size_type __pos = npos) const noexcept
+      { return this->rfind(__str._M_str, __pos, __str._M_len); }
+
+      size_type
+      rfind(_CharT __c, size_type __pos = npos) const noexcept;
+
+      size_type
+      rfind(const _CharT* __str, size_type __pos, size_type __n) const;
+
+      size_type
+      rfind(const _CharT* __str, size_type __pos = npos) const noexcept
+      { return this->rfind(__str, __pos, traits_type::length(__str)); }
+
+      size_type
+      find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
+      { return this->find_first_of(__str._M_str, __pos, __str._M_len); }
+
+      size_type
+      find_first_of(_CharT __c, size_type __pos = 0) const noexcept
+      { return this->find(__c, __pos); }
+
+      size_type
+      find_first_of(const _CharT* __str, size_type __pos, size_type __n) const;
+
+      size_type
+      find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
+      { return this->find_first_of(__str, __pos, traits_type::length(__str)); }
+
+      size_type
+      find_last_of(basic_string_view __str,
+		   size_type __pos = npos) const noexcept
+      { return this->find_last_of(__str._M_str, __pos, __str._M_len); }
+
+      size_type
+      find_last_of(_CharT __c, size_type __pos=npos) const noexcept
+      { return this->rfind(__c, __pos); }
+
+      size_type
+      find_last_of(const _CharT* __str, size_type __pos, size_type __n) const;
+
+      size_type
+      find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
+      { return this->find_last_of(__str, __pos, traits_type::length(__str)); }
+
+      size_type
+      find_first_not_of(basic_string_view __str,
+			size_type __pos = 0) const noexcept
+      { return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
+
+      size_type
+      find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
+
+      size_type
+      find_first_not_of(const _CharT* __str,
+			size_type __pos, size_type __n) const;
+
+      size_type
+      find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
+      {
+	return this->find_first_not_of(__str, __pos,
+				       traits_type::length(__str));
+      }
+
+      size_type
+      find_last_not_of(basic_string_view __str,
+		       size_type __pos = npos) const noexcept
+      { return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
+
+      size_type
+      find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
+
+      size_type
+      find_last_not_of(const _CharT* __str,
+		       size_type __pos, size_type __n) const;
+
+      size_type
+      find_last_not_of(const _CharT* __str,
+		       size_type __pos = npos) const noexcept
+      {
+	return this->find_last_not_of(__str, __pos,
+				      traits_type::length(__str));
+      }
+
+    private:
+
+      //  Compute max_size similarly to how string does it.
+      static const size_type _S_max_size = (npos
+					  - sizeof(size_type) - sizeof(void*))
+					 / sizeof(value_type) / 4;
+
+      static constexpr const int
+      _S_compare(size_type __n1, size_type __n2) noexcept
+      {
+	return difference_type{__n1 - __n2} > std::numeric_limits<int>::max()
+	     ? std::numeric_limits<int>::max()
+	     : difference_type{__n1 - __n2} < std::numeric_limits<int>::min()
+	     ? std::numeric_limits<int>::min()
+	     : static_cast<int>(difference_type{__n1 - __n2});
+      }
+
+      size_t	    _M_len;
+      const _CharT* _M_str;
+    };
+
+
+  // [string.view.comparison], non-member basic_string_view comparison functions
+
+  namespace __detail
+  {
+    //  Identity transform to make ADL work with just one argument.
+    //  See n3766.html.
+    template<typename _Tp = void>
+      struct __identity
+      { typedef _Tp type; };
+
+    template<>
+      struct __identity<void>;
+
+    template<typename _Tp>
+      using __idt = typename __identity<_Tp>::type;
+  }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator==(basic_string_view<_CharT, _Traits> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) == 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator==(basic_string_view<_CharT, _Traits> __x,
+               __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
+    { return __x.compare(__y) == 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator==(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) == 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator!=(basic_string_view<_CharT, _Traits> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return !(__x == __y); }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator!=(basic_string_view<_CharT, _Traits> __x,
+               __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
+    { return !(__x == __y); }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator!=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return !(__x == __y); }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator< (basic_string_view<_CharT, _Traits> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) < 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator< (basic_string_view<_CharT, _Traits> __x,
+               __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
+    { return __x.compare(__y) < 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator< (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) < 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator> (basic_string_view<_CharT, _Traits> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) > 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator> (basic_string_view<_CharT, _Traits> __x,
+               __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
+    { return __x.compare(__y) > 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator> (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) > 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator<=(basic_string_view<_CharT, _Traits> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) <= 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator<=(basic_string_view<_CharT, _Traits> __x,
+               __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
+    { return __x.compare(__y) <= 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator<=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) <= 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator>=(basic_string_view<_CharT, _Traits> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) >= 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator>=(basic_string_view<_CharT, _Traits> __x,
+               __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
+    { return __x.compare(__y) >= 0; }
+
+  template<typename _CharT, typename _Traits>
+    bool
+    operator>=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
+               basic_string_view<_CharT, _Traits> __y) noexcept
+    { return __x.compare(__y) >= 0; }
+
+  // [string.view.comparison], sufficient additional overloads of comparison functions
+
+  // [string.view.nonmem], other non-member basic_string_view functions
+  template<typename _CharT, typename _Traits = char_traits<_CharT>,
+           typename _Allocator = allocator<_CharT>>
+    basic_string<_CharT, _Traits, _Allocator>
+    to_string(basic_string_view<_CharT, _Traits> __str,
+	      const _Allocator& __alloc = _Allocator())
+    {
+      return basic_string<_CharT, _Traits, _Allocator>
+			(__str.begin(), __str.end(), __alloc);
+    }
+
+  template<typename _CharT, typename _Traits>
+    basic_ostream<_CharT, _Traits>&
+      operator<<(basic_ostream<_CharT, _Traits>& __os,
+                 basic_string_view<_CharT,_Traits> __str)
+      { return __ostream_insert(__os, __str.data(), __str.size()); }
+
+
+  // basic_string_view typedef names
+
+  using string_view = basic_string_view<char>;
+#ifdef _GLIBCXX_USE_WCHAR_T
+  using wstring_view = basic_string_view<wchar_t>;
+#endif
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+  using u16string_view = basic_string_view<char16_t>;
+  using u32string_view = basic_string_view<char32_t>;
+#endif
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace experimental
+
+
+  // [string.view.hash], hash support:
+
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+  template<typename _Tp>
+    struct hash;
+
+  template<>
+    struct hash<experimental::string_view>
+    : public __hash_base<size_t, experimental::string_view>
+    {
+      size_t
+      operator()(const experimental::string_view& __str) const noexcept
+      { return std::_Hash_impl::hash(__str.data(), __str.length()); }
+    };
+
+  template<>
+    struct __is_fast_hash<hash<experimental::string_view>> : std::false_type
+    { };
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+  template<>
+    struct hash<experimental::wstring_view>
+    : public __hash_base<size_t, wstring>
+    {
+      size_t
+      operator()(const experimental::wstring_view& __s) const noexcept
+      { return std::_Hash_impl::hash(__s.data(),
+                                     __s.length() * sizeof(wchar_t)); }
+    };
+
+  template<>
+    struct __is_fast_hash<hash<experimental::wstring_view>> : std::false_type
+    { };
+#endif
+
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+  template<>
+    struct hash<experimental::u16string_view>
+    : public __hash_base<size_t, experimental::u16string_view>
+    {
+      size_t
+      operator()(const experimental::u16string_view& __s) const noexcept
+      { return std::_Hash_impl::hash(__s.data(),
+                                     __s.length() * sizeof(char16_t)); }
+    };
+
+  template<>
+    struct __is_fast_hash<hash<experimental::u16string_view>> : std::false_type
+    { };
+
+  template<>
+    struct hash<experimental::u32string_view>
+    : public __hash_base<size_t, experimental::u32string_view>
+    {
+      size_t
+      operator()(const experimental::u32string_view& __s) const noexcept
+      { return std::_Hash_impl::hash(__s.data(),
+                                     __s.length() * sizeof(char32_t)); }
+    };
+
+  template<>
+    struct __is_fast_hash<hash<experimental::u32string_view>> : std::false_type
+    { };
+#endif
+_GLIBCXX_END_NAMESPACE_VERSION
+
+namespace experimental
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+  // I added these EMSR.
+  inline namespace literals
+  {
+  inline namespace string_view_literals
+  {
+
+    inline basic_string_view<char>
+    operator""sv(const char* __str, size_t __len)
+    { return basic_string_view<char>{__str, __len}; }
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+    inline basic_string_view<wchar_t>
+    operator""sv(const wchar_t* __str, size_t __len)
+    { return basic_string_view<wchar_t>{__str, __len}; }
+#endif
+
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+    inline basic_string_view<char16_t>
+    operator""sv(const char16_t* __str, size_t __len)
+    { return basic_string_view<char16_t>{__str, __len}; }
+
+    inline basic_string_view<char32_t>
+    operator""sv(const char32_t* __str, size_t __len)
+    { return basic_string_view<char32_t>{__str, __len}; }
+#endif
+
+  }
+  }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace experimental
+} // namespace std
+
+#include <experimental/string_view.tcc>
+
+#endif // __cplusplus <= 201103L
+
+#endif // _GLIBCXX_EXPERIMENTAL_STRING_VIEW
diff --git a/libstdc++-v3/include/experimental/string_view.tcc b/libstdc++-v3/include/experimental/string_view.tcc
new file mode 100644
index 00000000000..78cbe99e80f
--- /dev/null
+++ b/libstdc++-v3/include/experimental/string_view.tcc
@@ -0,0 +1,230 @@
+// Components for manipulating non-owning sequences of characters -*- C++ -*-
+
+// Copyright (C) 2013 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file experimental/string_view.tcc
+ *  This is an internal header file, included by other library headers.
+ *  Do not attempt to use it directly. @headername{string_view}
+ */
+
+//
+// ISO C++ 14882: 21  Strings library
+//
+
+#ifndef _GLIBCXX_EXPERIMENTAL_STRING_VIEW_TCC
+#define _GLIBCXX_EXPERIMENTAL_STRING_VIEW_TCC 1
+
+#pragma GCC system_header
+
+#if __cplusplus <= 201103L
+# include <bits/c++14_warning.h>
+#else
+
+namespace std //_GLIBCXX_VISIBILITY(default)
+{
+namespace experimental
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find(const _CharT* __str, size_type __pos, size_type __n) const noexcept
+    {
+      __glibcxx_requires_string_len(__str, __n);
+
+      if (__n == 0)
+	return __pos <= this->_M_len ? __pos : npos;
+
+      if (__n <= this->_M_len)
+	{
+	  for (; __pos <= this->_M_len - __n; ++__pos)
+	    if (traits_type::eq(this->_M_str[__pos], __str[0])
+		&& traits_type::compare(this->_M_str + __pos + 1,
+					__str + 1, __n - 1) == 0)
+	      return __pos;
+	}
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find(_CharT __c, size_type __pos) const noexcept
+    {
+      size_type __ret = npos;
+      if (__pos < this->_M_len)
+	{
+	  const size_type __n = this->_M_len - __pos;
+	  const _CharT* __p = traits_type::find(this->_M_str + __pos, __n, __c);
+	  if (__p)
+	    __ret = __p - this->_M_str;
+	}
+      return __ret;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept
+    {
+      __glibcxx_requires_string_len(__str, __n);
+
+      if (__n <= this->_M_len)
+	{
+	  __pos = std::min(size_type(this->_M_len - __n), __pos);
+	  do
+	    {
+	      if (traits_type::compare(this->_M_str + __pos, __str, __n) == 0)
+		return __pos;
+	    }
+	  while (__pos-- > 0);
+	}
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    rfind(_CharT __c, size_type __pos) const noexcept
+    {
+      size_type __size = this->_M_len;
+      if (__size > 0)
+	{
+	  if (--__size > __pos)
+	    __size = __pos;
+	  for (++__size; __size-- > 0; )
+	    if (traits_type::eq(this->_M_str[__size], __c))
+	      return __size;
+	}
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find_first_of(const _CharT* __str, size_type __pos, size_type __n) const
+    {
+      __glibcxx_requires_string_len(__str, __n);
+      for (; __n && __pos < this->_M_len; ++__pos)
+	{
+	  const _CharT* __p = traits_type::find(__str, __n,
+						this->_M_str[__pos]);
+	  if (__p)
+	    return __pos;
+	}
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find_last_of(const _CharT* __str, size_type __pos, size_type __n) const
+    {
+      __glibcxx_requires_string_len(__str, __n);
+      size_type __size = this->size();
+      if (__size && __n)
+	{
+	  if (--__size > __pos)
+	    __size = __pos;
+	  do
+	    {
+	      if (traits_type::find(__str, __n, this->_M_str[__size]))
+		return __size;
+	    }
+	  while (__size-- != 0);
+	}
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find_first_not_of(const _CharT* __str, size_type __pos, size_type __n) const
+    {
+      __glibcxx_requires_string_len(__str, __n);
+      for (; __pos < this->_M_len; ++__pos)
+	if (!traits_type::find(__str, __n, this->_M_str[__pos]))
+	  return __pos;
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find_first_not_of(_CharT __c, size_type __pos) const noexcept
+    {
+      for (; __pos < this->_M_len; ++__pos)
+	if (!traits_type::eq(this->_M_str[__pos], __c))
+	  return __pos;
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find_last_not_of(const _CharT* __str, size_type __pos, size_type __n) const
+    {
+      __glibcxx_requires_string_len(__str, __n);
+      size_type __size = this->_M_len;
+      if (__size)
+	{
+	  if (--__size > __pos)
+	    __size = __pos;
+	  do
+	    {
+	      if (!traits_type::find(__str, __n, this->_M_str[__size]))
+		return __size;
+	    }
+	  while (__size--);
+	}
+      return npos;
+    }
+
+  template<typename _CharT, typename _Traits>
+    typename basic_string_view<_CharT, _Traits>::size_type
+    basic_string_view<_CharT, _Traits>::
+    find_last_not_of(_CharT __c, size_type __pos) const noexcept
+    {
+      size_type __size = this->_M_len;
+      if (__size)
+	{
+	  if (--__size > __pos)
+	    __size = __pos;
+	  do
+	    {
+	      if (!traits_type::eq(this->_M_str[__size], __c))
+		return __size;
+	    }
+	  while (__size--);
+	}
+      return npos;
+    }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace experimental
+} // namespace std
+
+#endif // __cplusplus <= 201103L
+
+#endif // _GLIBCXX_EXPERIMENTAL_STRING_VIEW_TCC