Imported from /home/lorry/working-area/delta_boost-tarball/boost_1_54_0.tar.bz2.boost_1_54_0baserock/morph

1 files changed, 110 insertions, 0 deletions

diff --git a/libs/local_function/example/scope_exit.cpp b/libs/local_function/example/scope_exit.cpp
new file mode 100644
index 000000000..607bf6be0
--- /dev/null
+++ b/libs/local_function/example/scope_exit.cpp
@@ -0,0 +1,110 @@
+
+// Copyright (C) 2009-2012 Lorenzo Caminiti
+// Distributed under the Boost Software License, Version 1.0
+// (see accompanying file LICENSE_1_0.txt or a copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+// Home at http://www.boost.org/libs/local_function
+
+#include "scope_exit.hpp"
+#include <boost/foreach.hpp>
+#include <boost/typeof/typeof.hpp>
+#include <boost/typeof/std/vector.hpp>
+#include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP()
+#include <boost/detail/lightweight_test.hpp>
+#include <vector>
+#include <iostream>
+#include <sstream>
+
+class person {
+    friend class world;
+public:
+    typedef unsigned int id_t;
+    typedef unsigned int evolution_t;
+
+    person(void): id_(0), evolution_(0) {}
+
+    friend std::ostream& operator<<(std::ostream& o, person const& p) {
+        return o << "person(" << p.id_ << ", " << p.evolution_ << ")";
+    }
+private:
+    id_t id_;
+    evolution_t evolution_;
+};
+BOOST_TYPEOF_REGISTER_TYPE(person)
+
+class world {
+public:
+    typedef unsigned int id_t;
+
+    world(void): next_id_(1) {}
+
+    void add_person(person const& a_person);
+
+    friend std::ostream& operator<<(std::ostream& o, world const& w) {
+        o << "world(" << w.next_id_ << ", {";
+        BOOST_FOREACH(person const& p, w.persons_) {
+            o << " " << p << ", ";
+        }
+        return o << "})";
+    }
+private:
+    id_t next_id_;
+    std::vector<person> persons_;
+};
+BOOST_TYPEOF_REGISTER_TYPE(world)
+
+void world::add_person(person const& a_person) {
+    persons_.push_back(a_person);
+
+    // This block must be no-throw.
+    //[scope_exit
+    person& p = persons_.back();
+    person::evolution_t checkpoint = p.evolution_;
+
+    SCOPE_EXIT(const bind checkpoint, const bind& p, bind this_) {
+        if (checkpoint == p.evolution_) this_->persons_.pop_back();
+    } SCOPE_EXIT_END
+    //]
+
+    // ...
+
+    checkpoint = ++p.evolution_;
+
+    // Assign new id to the person.
+    world::id_t const prev_id = p.id_;
+    p.id_ = next_id_++;
+    SCOPE_EXIT(const bind checkpoint, const bind prev_id, bind& p,
+            bind& next_id_) {
+        if (checkpoint == p.evolution_) {
+            next_id_ = p.id_;
+            p.id_ = prev_id;
+        }
+    } SCOPE_EXIT_END
+
+    // ...
+
+    checkpoint = ++p.evolution_;
+}
+
+int main(void) {
+    person adam, eva;
+    std::ostringstream oss;
+    oss << adam;
+    std::cout << oss.str() << std::endl;
+    BOOST_TEST(oss.str() == "person(0, 0)");
+
+    oss.str("");
+    oss << eva;
+    std::cout << oss.str() << std::endl;
+    BOOST_TEST(oss.str() == "person(0, 0)");
+
+    world w;
+    w.add_person(adam);
+    w.add_person(eva);
+    oss.str("");
+    oss << w;
+    std::cout << oss.str() << std::endl;
+    BOOST_TEST(oss.str() == "world(3, { person(1, 2),  person(2, 2), })");
+    return boost::report_errors();
+}
+