You can now manually disable move semantics.

This may be useful in MSVC to work around a bug described in Trac #10399

doc/91_relnotes.qbk

@@ -16,6 +16,7 @@
 * `boost::none_t` is no longer convertible from literal `0`. This avoids a bug where `optional<rational<int>> oi = 0;` would initialize an optional object with no contained value.
 * Improved the trick that prevents streaming out `optional` without header `optional_io.hpp` by using safe-bool idiom. This addresses [@https://svn.boost.org/trac/boost/ticket/10825 Trac #10825]
 * IOStream operators are now mentioned in documentation.
+* Added a way to manually disable move semantics: just define macro `BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES`. This can be used to work around [@https://svn.boost.org/trac/boost/ticket/10399 Trac #10399]
 
 
 [heading Boost Release 1.57]

doc/html/boost_optional/relnotes.html

@@ -47,6 +47,11 @@
 <li class="listitem">
           IOStream operators are now mentioned in documentation.
         </li>
+<li class="listitem">
+          Added a way to manually disable move semantics: just define macro <code class="computeroutput"><span class="identifier">BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES</span></code>.
+          This can be used to work around <a href="https://svn.boost.org/trac/boost/ticket/10399" target="_top">Trac
+          #10399</a>
+        </li>
 </ul></div>
 <h4>
 <a name="boost_optional.relnotes.h1"></a>

doc/html/index.html

@@ -138,7 +138,7 @@
 </div>
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
-<td align="left"><p><small>Last revised: January 20, 2015 at 23:06:39 GMT</small></p></td>
+<td align="left"><p><small>Last revised: January 21, 2015 at 13:59:23 GMT</small></p></td>
 <td align="right"><div class="copyright-footer"></div></td>
 </tr></table>
 <hr>

include/boost/optional/optional.hpp

@@ -1,5 +1,5 @@
 // Copyright (C) 2003, 2008 Fernando Luis Cacciola Carballal.
-// Copyright (C) 2014 Andrzej Krzemienski.
+// Copyright (C) 2014, 2015 Andrzej Krzemienski.
 //
 // Use, modification, and distribution is subject to the Boost Software
 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
@@ -57,6 +57,10 @@
 
 #include <boost/optional/optional_fwd.hpp>
 
+#if (defined BOOST_NO_CXX11_RVALUE_REFERENCES) || (defined BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES)
+#define BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
+#endif
+
 #if BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION,<=700)
 // AFAICT only Intel 7 correctly resolves the overload set
 // that includes the in-place factory taking functions,
@@ -148,7 +152,7 @@ struct types_when_isnt_ref
 {
   typedef T const& reference_const_type ;
   typedef T &      reference_type ;
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
   typedef T &&     rval_reference_type ;
   typedef T &&     reference_type_of_temporary_wrapper;
 #ifdef BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES
@@ -171,7 +175,7 @@ struct types_when_is_ref
 
   typedef raw_type&  reference_const_type ;
   typedef raw_type&  reference_type ;
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
   typedef BOOST_DEDUCED_TYPENAME remove_const<raw_type>::type&& rval_reference_type ;
   typedef raw_type&  reference_type_of_temporary_wrapper;
   static reference_type move(reference_type r) { return r; }
@@ -226,7 +230,7 @@ class optional_base : public optional_tag
   protected:
     typedef BOOST_DEDUCED_TYPENAME types::reference_type       reference_type ;
     typedef BOOST_DEDUCED_TYPENAME types::reference_const_type reference_const_type ;
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     typedef BOOST_DEDUCED_TYPENAME types::rval_reference_type  rval_reference_type ;
     typedef BOOST_DEDUCED_TYPENAME types::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ;
 #endif
@@ -255,7 +259,7 @@ class optional_base : public optional_tag
       construct(val);
     }
 
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // move-construct an optional<T> initialized from an rvalue-ref to 'val'.
     // Can throw if T::T(T&&) does
     optional_base ( rval_reference_type val )
@@ -286,7 +290,7 @@ class optional_base : public optional_tag
         construct(rhs.get_impl());
     }
 
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Creates a deep move of another optional<T>
     // Can throw if T::T(T&&) does
     optional_base ( optional_base&& rhs )
@@ -298,7 +302,7 @@ class optional_base : public optional_tag
     }
 #endif
 
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 
     template<class Expr, class PtrExpr>
     explicit optional_base ( Expr&& expr, PtrExpr const* tag )
@@ -342,7 +346,7 @@ class optional_base : public optional_tag
       }
     }
     
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Assigns from another optional<T> (deep-moves the rhs value)
     void assign ( optional_base&& rhs )
     {
@@ -377,7 +381,7 @@ class optional_base : public optional_tag
       }
     }
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // move-assigns from another _convertible_ optional<U> (deep-moves from the rhs value)
     template<class U>
     void assign ( optional<U>&& rhs )
@@ -405,7 +409,7 @@ class optional_base : public optional_tag
       else construct(val);
     }
     
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Assigns from a T (deep-moves the rhs value)
     void assign ( rval_reference_type val )
     {
@@ -421,7 +425,7 @@ class optional_base : public optional_tag
 
 #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     template<class Expr, class ExprPtr>
     void assign_expr ( Expr&& expr, ExprPtr const* tag )
     {
@@ -466,7 +470,7 @@ class optional_base : public optional_tag
        m_initialized = true ;
      }
      
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     void construct ( rval_reference_type val )
      {
        ::new (m_storage.address()) internal_type( types::move(val) ) ;
@@ -475,7 +479,7 @@ class optional_base : public optional_tag
 #endif
 
 
-#if (!defined BOOST_NO_CXX11_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+#if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES)
     // Constructs in-place
     // upon exception *this is always uninitialized
     template<class... Args>
@@ -485,7 +489,7 @@ class optional_base : public optional_tag
        ::new (m_storage.address()) internal_type( boost::forward<Args>(args)... );
        m_initialized = true ;
      }
-#elif (!defined BOOST_NO_CXX11_RVALUE_REFERENCES)
+#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
     template<class Arg>
     void emplace_assign ( Arg&& arg )
      {
@@ -513,7 +517,7 @@ class optional_base : public optional_tag
 
 #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Constructs in-place using the given factory
     template<class Expr>
     void construct ( Expr&& factory, in_place_factory_base const* )
@@ -584,7 +588,7 @@ class optional_base : public optional_tag
 
 #endif
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Constructs using any expression implicitly convertible to the single argument
     // of a one-argument T constructor.
     // Converting constructions of optional<T> from optional<U> uses this function with
@@ -642,7 +646,7 @@ class optional_base : public optional_tag
     // For VC<=70 compilers this workaround dosen't work becasue the comnpiler issues and error
     // instead of choosing the wrong overload
     //
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Notice that 'Expr' will be optional<T> or optional<U> (but not optional_base<..>)
     template<class Expr>
     void construct ( Expr&& expr, optional_tag const* )
@@ -673,7 +677,7 @@ class optional_base : public optional_tag
 
     void assign_value ( argument_type val, is_not_reference_tag ) { get_impl() = val; }
     void assign_value ( argument_type val, is_reference_tag     ) { construct(val); }
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     void assign_value ( rval_reference_type val, is_not_reference_tag ) { get_impl() = static_cast<rval_reference_type>(val); }
     void assign_value ( rval_reference_type val, is_reference_tag     ) { construct( static_cast<rval_reference_type>(val) ); }
 #endif
@@ -750,7 +754,7 @@ class optional : public optional_detail::optional_base<T>
     typedef BOOST_DEDUCED_TYPENAME base::value_type           value_type ;
     typedef BOOST_DEDUCED_TYPENAME base::reference_type       reference_type ;
     typedef BOOST_DEDUCED_TYPENAME base::reference_const_type reference_const_type ;
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     typedef BOOST_DEDUCED_TYPENAME base::rval_reference_type  rval_reference_type ;
     typedef BOOST_DEDUCED_TYPENAME base::reference_type_of_temporary_wrapper reference_type_of_temporary_wrapper ;
 #endif
@@ -770,7 +774,7 @@ class optional : public optional_detail::optional_base<T>
     // Can throw if T::T(T const&) does
     optional ( argument_type val ) : base(val) {}
 
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Creates an optional<T> initialized with 'move(val)'.
     // Can throw if T::T(T &&) does
     optional ( rval_reference_type val ) : base( boost::forward<T>(val) ) 
@@ -795,7 +799,7 @@ class optional : public optional_detail::optional_base<T>
         this->construct(rhs.get());
     }
     
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Creates a deep move of another convertible optional<U>
     // Requires a valid conversion from U to T.
     // Can throw if T::T(U&&) does
@@ -819,7 +823,7 @@ class optional : public optional_detail::optional_base<T>
     //       even though explicit overloads are present for these.
     // Depending on the above some T ctor is called.
     // Can throw if the resolved T ctor throws.
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 
 
   template<class Expr>
@@ -834,14 +838,14 @@ class optional : public optional_detail::optional_base<T>
 #else
     template<class Expr>
     explicit optional ( Expr const& expr ) : base(expr,boost::addressof(expr)) {}
-#endif // !defined BOOST_NO_CXX11_RVALUE_REFERENCES
+#endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 #endif // !defined BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
 
     // Creates a deep copy of another optional<T>
     // Can throw if T::T(T const&) does
     optional ( optional const& rhs ) : base( static_cast<base const&>(rhs) ) {}
 
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 	// Creates a deep move of another optional<T>
 	// Can throw if T::T(T&&) does
 	optional ( optional && rhs ) 
@@ -856,7 +860,7 @@ class optional : public optional_detail::optional_base<T>
 #if !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION)
     // Assigns from an expression. See corresponding constructor.
     // Basic Guarantee: If the resolved T ctor throws, this is left UNINITIALIZED
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 
     template<class Expr>
     BOOST_DEDUCED_TYPENAME boost::disable_if_c<
@@ -878,7 +882,7 @@ class optional : public optional_detail::optional_base<T>
         this->assign_expr(expr,boost::addressof(expr));
         return *this ;
       }
-#endif // !defined  BOOST_NO_CXX11_RVALUE_REFERENCES
+#endif // !defined  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 #endif // !defined(BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT) && !defined(BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION)
 
     // Copy-assigns from another convertible optional<U> (converts && deep-copies the rhs value)
@@ -891,7 +895,7 @@ class optional : public optional_detail::optional_base<T>
         return *this ;
       }
       
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Move-assigns from another convertible optional<U> (converts && deep-moves the rhs value)
     // Requires a valid conversion from U to T.
     // Basic Guarantee: If T::T( U && ) throws, this is left UNINITIALIZED
@@ -912,7 +916,7 @@ class optional : public optional_detail::optional_base<T>
         return *this ;
       }
 
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Assigns from another optional<T> (deep-moves the rhs value)
     optional& operator= ( optional && rhs ) 
 	  BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value && ::boost::is_nothrow_move_assignable<T>::value)
@@ -930,7 +934,7 @@ class optional : public optional_detail::optional_base<T>
         return *this ;
       }
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Assigns from a T (deep-moves the rhs value)
     optional& operator= ( rval_reference_type val )
       {
@@ -949,7 +953,7 @@ class optional : public optional_detail::optional_base<T>
         return *this ;
       }
       
-#if (!defined BOOST_NO_CXX11_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+#if (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) && (!defined BOOST_NO_CXX11_VARIADIC_TEMPLATES)
     // Constructs in-place
     // upon exception *this is always uninitialized
     template<class... Args>
@@ -957,7 +961,7 @@ class optional : public optional_detail::optional_base<T>
      {
        this->emplace_assign( boost::forward<Args>(args)... );
      }
-#elif (!defined BOOST_NO_CXX11_RVALUE_REFERENCES)
+#elif (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES)
     template<class Arg>
     void emplace ( Arg&& arg )
      {
@@ -1004,7 +1008,7 @@ class optional : public optional_detail::optional_base<T>
     // Returns a reference to the value if this is initialized, otherwise,
     // the behaviour is UNDEFINED
     // No-throw
-#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
+#if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) 
     reference_const_type operator *() const& { return this->get() ; }
     reference_type       operator *() &      { return this->get() ; }
     reference_type_of_temporary_wrapper operator *() && { return boost::move(this->get()) ; }
@@ -1013,7 +1017,7 @@ class optional : public optional_detail::optional_base<T>
     reference_type       operator *()       { return this->get() ; }
 #endif // !defined BOOST_NO_CXX11_REF_QUALIFIERS
 
-#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
+#if (!defined BOOST_NO_CXX11_REF_QUALIFIERS) && (!defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES) 
     reference_const_type value() const&
       { 
         if (this->is_initialized())
@@ -1075,7 +1079,7 @@ class optional : public optional_detail::optional_base<T>
         else
           return boost::forward<U>(v);
       }
-#elif !defined BOOST_NO_CXX11_RVALUE_REFERENCES
+#elif !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     template <class U>
     value_type value_or ( U&& v ) const 
       {
@@ -1130,7 +1134,7 @@ class optional : public optional_detail::optional_base<T>
     BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()
 } ;
 
-#ifndef  BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 template<class T>
 class optional<T&&>
 {
@@ -1440,7 +1444,7 @@ struct swap_selector<true>
     }
 };
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 template<>
 struct swap_selector<false>
 {
@@ -1497,7 +1501,7 @@ struct swap_selector<false>
         }
     }
 };
-#endif // !defined BOOST_NO_CXX11_RVALUE_REFERENCES
+#endif // !defined BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
 
 } // namespace optional_detail
 

test/Jamfile.v2

@@ -33,6 +33,7 @@ import testing ;
     [ run optional_test_value_access.cpp ]
     [ run optional_test_emplace.cpp ]
     [ run optional_test_minimum_requirements.cpp ]
+    [ run optional_test_msvc_bug_workaround.cpp ]
     [ compile-fail optional_test_fail1.cpp ]
     [ compile-fail optional_test_fail3a.cpp ]
     [ compile-fail optional_test_fail3b.cpp ]

test/optional_test_msvc_bug_workaround.cpp

@@ -0,0 +1,41 @@
+// Copyright (C) 2015 Andrzej Krzemienski.
+//
+// Use, modification, and distribution is subject to 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)
+//
+// See http://www.boost.org/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  akrzemi1@gmail.com
+
+#define BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES
+#include "boost/optional/optional.hpp"
+
+#ifdef __BORLANDC__
+#pragma hdrstop
+#endif
+
+#include "boost/core/lightweight_test.hpp"
+
+
+struct Wrapper
+{
+  operator int () { return 9; }
+  operator boost::optional<int> () { return 7; }
+};
+
+void test()
+{
+#if (!defined BOOST_NO_CXX11_RVALUE_REFERENCES)
+  boost::optional<int> v = Wrapper();
+  BOOST_TEST(v);
+  BOOST_TEST_EQ(*v, 7);
+#endif
+} 
+
+int main()
+{
+  test();
+  return boost::report_errors();
+}