Add tests for enable_shared_from

test/weak_from_test2.cpp

@@ -0,0 +1,57 @@
+
+//  weak_from_test2.cpp
+//
+//  Tests weak_from in a destructor
+//
+//  Copyright 2014, 2015, 2019 Peter Dimov
+//
+//  Distributed under the Boost Software License, Version 1.0.
+//  http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/smart_ptr/enable_shared_from.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+class X: public boost::enable_shared_from
+{
+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();
+}