Added ref-qualifiers to some accessors

include/boost/optional/optional.hpp

@@ -958,9 +958,40 @@ 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
+    reference_const_type operator *() const& { return this->get() ; }
+    reference_type       operator *() &      { return this->get() ; }
+    rval_reference_type  operator *() &&     { return boost::move(this->get()) ; }
+#else
     reference_const_type operator *() const { return this->get() ; }
     reference_type       operator *()       { return this->get() ; }
-    
+#endif
+
+#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
+    reference_const_type value() const&
+      { 
+        if (this->is_initialized())
+          return this->get() ;
+        else
+          throw_exception(bad_optional_access("Attempted to access the value of an uninitialized optional object."));
+      }
+      
+    reference_type value() &
+      { 
+        if (this->is_initialized())
+          return this->get() ;
+        else
+          throw_exception(bad_optional_access("Attempted to access the value of an uninitialized optional object."));
+      }
+      
+    rval_reference_type value() &&
+      { 
+        if (this->is_initialized())
+          return boost::move(this->get()) ;
+        else
+          throw_exception(bad_optional_access("Attempted to access the value of an uninitialized optional object."));
+      }
+#else 
     reference_const_type value() const
       { 
         if (this->is_initialized())
@@ -976,10 +1007,20 @@ class optional : public optional_detail::optional_base<T>
         else
           throw_exception(bad_optional_access("Attempted to access the value of an uninitialized optional object."));
       }
+#endif
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
     template <class U>
-    value_type value_or ( U&& v ) const { return this->is_initialized() ? get() : static_cast<value_type>(boost::forward<U>(v)); }
+    value_type value_or ( U&& v ) const&
+    { return this->is_initialized() ? get() : static_cast<value_type>(boost::forward<U>(v)); }
+    
+    template <class U>
+    value_type value_or ( U&& v ) && 
+    { return this->is_initialized() ? boost::move(get()) : static_cast<value_type>(boost::forward<U>(v)); }
+#elif !defined BOOST_NO_CXX11_RVALUE_REFERENCES
+    template <class U>
+    value_type value_or ( U&& v ) const 
+    { return this->is_initialized() ? get() : static_cast<value_type>(boost::forward<U>(v)); }
 #else
     template <class U>
     value_type value_or ( U const& v ) const { return this->is_initialized() ? get() : static_cast<value_type>(v); }

test/optional_test_common.cpp

@@ -37,7 +37,7 @@ void assertion_failed (char const * expr, char const * func, char const * file,
 
 using boost::optional ;
 
-template<class T> inline void unused_variable ( T ) {}
+template<class T> inline void unused_variable ( const T& ) {}
 
 #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
 using boost::swap ;

test/optional_test_value_access.cpp

@@ -128,6 +128,35 @@ void test_function_value_or()
     BOOST_CHECK(FatToIntConverter::conversions == 1);
 }
 
+#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
+struct MoveOnly
+{
+    explicit MoveOnly(int){}
+    MoveOnly(MoveOnly &&){}
+    void operator=(MoveOnly &&);
+private:
+    MoveOnly(MoveOnly const&);
+    void operator=(MoveOnly const&);
+};
+
+optional<MoveOnly> makeMoveOnly()
+{
+    return MoveOnly(1);
+}
+
+// compile-time test
+void test_move_only_getters()
+{
+    MoveOnly m1 = *makeMoveOnly();
+    MoveOnly m2 = makeMoveOnly().value();
+    MoveOnly m3 = makeMoveOnly().value_or(MoveOnly(1));
+    unused_variable(m1);
+    unused_variable(m2);
+    unused_variable(m3);
+}
+
+#endif
+
 int test_main( int, char* [] )
 {
   try