Ticket #1841: 14-optional-partial-rvalue.patch

boost/optional/optional.hpp

@@ -152 +152 @@
 {
   typedef T const& reference_const_type ;
   typedef T &      reference_type ;
+#ifdef BOOST_HAS_RVALUE_REFS
+  typedef T &&     rreference_type ;
+#endif
   typedef T const* pointer_const_type ;
   typedef T *      pointer_type ;
   typedef T const& argument_type ;
@@ -163 +166 @@
 
   typedef raw_type& reference_const_type ;
   typedef raw_type& reference_type ;
+#ifdef BOOST_HAS_RVALUE_REFS
+  typedef raw_type&& rreference_type ;
+#endif
   typedef raw_type* pointer_const_type ;
   typedef raw_type* pointer_type ;
   typedef raw_type& argument_type ;
@@ -205 +211 @@
 
     typedef BOOST_DEDUCED_TYPENAME types::reference_type       reference_type ;
     typedef BOOST_DEDUCED_TYPENAME types::reference_const_type reference_const_type ;
+#ifdef BOOST_HAS_RVALUE_REFS
+    typedef BOOST_DEDUCED_TYPENAME types::rreference_type      rreference_type ;
+#endif
     typedef BOOST_DEDUCED_TYPENAME types::pointer_type         pointer_type ;
     typedef BOOST_DEDUCED_TYPENAME types::pointer_const_type   pointer_const_type ;
     typedef BOOST_DEDUCED_TYPENAME types::argument_type        argument_type ;
@@ -240 +249 @@
         construct(val);
     }
 
+#ifdef BOOST_HAS_RVALUE_REFS
+    // Creates an optional<T> move-constructed from 'val'
+    // Can throw if T::T(T &&) does
+    optional_base ( rreference_type val )
+      :
+      m_initialized(false)
+    {
+      construct(std::forward<T>(val));
+    }
+
+    // Creates an optional<T> move-constructed from 'val' IFF cond is true, otherwise creates an uninitialzed optional<T>.
+    // Can throw if T::T(T &&) does
+    optional_base ( bool cond, rreference_type val )
+      :
+      m_initialized(false)
+    {
+      if ( cond )
+        construct(std::forward<T>(val));
+    }
+#endif
+
     // Creates a deep copy of another optional<T>
     // Can throw if T::T(T const&) does
     optional_base ( optional_base const& rhs )
@@ -308 +338 @@
       else construct(val);
     }
 
+#ifdef BOOST_HAS_RVALUE_REFS
+    // Assigns from a T (moves the rhs value)
+    void assign ( rreference_type val )
+    {
+      if (is_initialized())
+           assign_value(std::forward<T>(val), is_reference_predicate() );
+      else construct(std::forward<T>(val));
+    }
+#endif
+
     // Assigns from "none", destroying the current value, if any, leaving this UNINITIALIZED
     // No-throw (assuming T::~T() doesn't)
     void assign ( none_t ) { destroy(); }
@@ -347 +387 @@
        m_initialized = true ;
      }
 
+#ifdef BOOST_HAS_RVALUE_REFS
+     void construct ( rreference_type val )
+     {
+       new (m_storage.address()) internal_type(std::forward<T>(val)) ;
+       m_initialized = true ;
+     }
+#endif
+
 #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
     // Constructs in-place using the given factory
     template<class Expr>
@@ -432 +480 @@
 
     void assign_value ( argument_type val, is_not_reference_tag ) { get_impl() = val; }
     void assign_value ( argument_type val, is_reference_tag     ) { construct(val); }
+#ifdef BOOST_HAS_RVALUE_REFS
+    void assign_value ( rreference_type val, is_not_reference_tag ) { get_impl() = std::forward<T>(val); }
+    void assign_value ( rreference_type val, is_reference_tag     ) { construct(std::forward<T>(val)); }
+#endif
 
     void destroy()
     {
@@ -509 +561 @@
     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 ;
+#ifdef BOOST_HAS_RVALUE_REFS
+    typedef BOOST_DEDUCED_TYPENAME base::rreference_type      rreference_type ;
+#endif
     typedef BOOST_DEDUCED_TYPENAME base::pointer_type         pointer_type ;
     typedef BOOST_DEDUCED_TYPENAME base::pointer_const_type   pointer_const_type ;
     typedef BOOST_DEDUCED_TYPENAME base::argument_type        argument_type ;
@@ -529 +584 @@
     // Can throw if T::T(T const&) does
     optional ( bool cond, argument_type val ) : base(cond,val) {}
 
+#ifdef BOOST_HAS_RVALUE_REFS
+    // Creates an optional<T> moved from 'val'.
+    // Can throw if T::T(T &&) does
+    optional ( rreference_type val ) : base(std::forward<value_type>(val)) {}
+
+    // Creates an optional<T> moved from 'val' IFF cond is true, otherwise creates an uninitialized optional.
+    // Can throw if T::T(T &&) does
+    optional ( bool cond, rreference_type val ) : base(cond,std::forward<value_type>(val)) {}
+#endif
+
 #ifndef BOOST_OPTIONAL_NO_CONVERTING_COPY_CTOR
     // NOTE: MSVC needs templated versions first
 
@@ -607 +672 @@
         return *this ;
       }
 
+#ifdef BOOST_HAS_RVALUE_REFS
+    // Assigns from a T (moves the rhs value)
+    // Basic Guarantee: If T::( T && ) throws, this is left UNINITIALIZED
+    optional& operator= ( rreference_type val )
+      {
+        this->assign( std::forward<T>(val) ) ;
+        return *this ;
+      }
+#endif
+
     // Assigns from a "none"
     // Which destroys the current value, if any, leaving this UNINITIALIZED
     // No-throw (assuming T::~T() doesn't)
@@ -671 +746 @@
   return optional<T>(cond,v);
 }
 
+#ifdef BOOST_HAS_RVALUE_REFS
+// Returns optional<T>(v)
+template<class T>
+inline
+optional<T> make_optional ( T && v  )
+{
+  return optional<T>(std::forward<T>(v));
+}
+
+// Returns optional<T>(cond,v)
+template<class T>
+inline
+optional<T> make_optional ( bool cond, T && v )
+{
+  return optional<T>(cond,std::forward<T>(v));
+}
+#endif
+
 // Returns a reference to the value if this is initialized, otherwise, the behaviour is UNDEFINED.
 // No-throw
 template<class T>