Add weak_from_this.

test/Jamfile.v2

@@ -175,5 +175,8 @@ import testing ;
           [ run weak_from_raw_test4.cpp ]
 
           [ compile sp_explicit_inst_test.cpp ]
+
+          [ run weak_from_this_test.cpp ]
+          [ run weak_from_this_test2.cpp ]
         ;
 }

test/weak_from_raw_test4.cpp

@@ -1,7 +1,7 @@
 //
 //  weak_from_raw_test4.cpp
 //
-//  As weak_from_raw_test2.cpp, but uses weak_from_this
+//  As weak_from_raw_test2.cpp, but uses weak_from_raw
 //  in the constructor
 //
 //  Copyright (c) 2014, 2015 Peter Dimov

test/weak_from_this_test.cpp

@@ -0,0 +1,52 @@
+#include <boost/config.hpp>
+
+//
+//  weak_from_this_test.cpp
+//
+//  Copyright (c) 2002, 2003, 2015 Peter Dimov
+//
+//  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
+//
+
+
+#include <boost/enable_shared_from_this.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/detail/lightweight_test.hpp>
+
+class V: public boost::enable_shared_from_this<V>
+{
+};
+
+void test()
+{
+    boost::shared_ptr<V> p( new V );
+
+    boost::weak_ptr<V> q = p;
+    BOOST_TEST( !q.expired() );
+
+    boost::weak_ptr<V> q2 = p->weak_from_this();
+    BOOST_TEST( !q2.expired() );
+    BOOST_TEST( !(q < q2) && !(q2 < q) );
+
+    V v2( *p );
+
+    boost::weak_ptr<V> q3 = v2.weak_from_this();
+    BOOST_TEST( q3.expired() );
+
+    *p = V();
+
+    boost::weak_ptr<V> q4 = p->shared_from_this();
+    BOOST_TEST( !q4.expired() );
+    BOOST_TEST( !(q < q4) && !(q4 < q) );
+    BOOST_TEST( !(q2 < q4) && !(q4 < q2) );
+}
+
+int main()
+{
+    test();
+    return boost::report_errors();
+}

test/weak_from_this_test2.cpp

@@ -0,0 +1,60 @@
+//
+//  weak_from_this_test2.cpp
+//
+//  Tests weak_from_this in a destructor
+//
+//  Copyright (c) 2014, 2015 Peter Dimov
+//
+//  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
+//
+
+#include <boost/smart_ptr/enable_shared_from_this.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+class X: public boost::enable_shared_from_this< X >
+{
+private:
+
+    boost::weak_ptr<X> px_;
+
+public:
+
+    X()
+    {
+        boost::weak_ptr<X> p1 = weak_from_this();
+        BOOST_TEST( p1._empty() );
+        BOOST_TEST( p1.expired() );
+    }
+
+    void check()
+    {
+        boost::weak_ptr<X> p2 = weak_from_this();
+        BOOST_TEST( !p2.expired() );
+
+        BOOST_TEST( p2.lock().get() == this );
+
+        px_ = p2;
+    }
+
+    ~X()
+    {
+        boost::weak_ptr<X> p3 = weak_from_this();
+        BOOST_TEST( p3.expired() );
+
+        BOOST_TEST( !(px_ < p3) && !(p3 < px_) );
+    }
+};
+
+int main()
+{
+    {
+        boost::shared_ptr< X > px( new X );
+        px->check();
+    }
+
+    return boost::report_errors();
+}