Make shared_from_this and weak_from_this private in enable_shared_from. Fixes #75.

include/boost/smart_ptr/enable_shared_from.hpp

@@ -3,7 +3,7 @@
 
 //  enable_shared_from.hpp
 //
-//  Copyright 2019 Peter Dimov
+//  Copyright 2019, 2020 Peter Dimov
 //
 //  Distributed under the Boost Software License, Version 1.0.
 //  See accompanying file LICENSE_1_0.txt or copy at
@@ -19,17 +19,21 @@ namespace boost
 
 class enable_shared_from: public enable_shared_from_this<enable_shared_from>
 {
+private:
+
+    using enable_shared_from_this<enable_shared_from>::shared_from_this;
+    using enable_shared_from_this<enable_shared_from>::weak_from_this;
 };
 
 
 template<class T> shared_ptr<T> shared_from( T * p )
 {
-    return shared_ptr<T>( p->enable_shared_from::shared_from_this(), p );
+    return shared_ptr<T>( p->enable_shared_from_this<enable_shared_from>::shared_from_this(), p );
 }
 
 template<class T> weak_ptr<T> weak_from( T * p ) BOOST_SP_NOEXCEPT
 {
-    return weak_ptr<T>( p->enable_shared_from::weak_from_this(), p );
+    return weak_ptr<T>( p->enable_shared_from_this<enable_shared_from>::weak_from_this(), p );
 }
 
 } // namespace boost

test/Jamfile

@@ -356,3 +356,6 @@ run allocate_unique_value_test.cpp ;
 run sp_guides_test.cpp ;
 run sp_guides_test2.cpp ;
 run wp_guides_test.cpp ;
+
+compile-fail shared_from_fail.cpp ;
+compile-fail weak_from_fail.cpp ;

test/shared_from_fail.cpp

@@ -0,0 +1,16 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/shared_ptr.hpp>
+#include <boost/smart_ptr/enable_shared_from.hpp>
+
+struct X: public boost::enable_shared_from
+{
+};
+
+int main()
+{
+    boost::shared_ptr<X> px( new X );
+    px->shared_from_this();
+}

test/weak_from_fail.cpp

@@ -0,0 +1,16 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/shared_ptr.hpp>
+#include <boost/smart_ptr/enable_shared_from.hpp>
+
+struct X: public boost::enable_shared_from
+{
+};
+
+int main()
+{
+    boost::shared_ptr<X> px( new X );
+    px->weak_from_this();
+}