DR 1579 PR c++/58051

gcc/cp:
	DR 1579
	PR c++/58051
	* typeck.c (check_return_expr): Lookup as an rvalue even when the
	types aren't the same.

gcc/testsuite:
	* g++.dg/cpp0x/elision_conv.C: New.

From-SVN: r212099

gcc/cp/ChangeLog

+2014-06-28  Jonathan Wakely  <jwakely@redhat.com>
+
+	DR 1579
+	PR c++/58051
+	* typeck.c (check_return_expr): Lookup as an rvalue even when the
+	types aren't the same.
+
 2014-06-27  Jason Merrill  <jason@redhat.com>
 
 	PR c++/61433

gcc/cp/typeck.c

@@ -8607,7 +8607,7 @@ check_return_expr (tree retval, bool *no_warning)
       if (VOID_TYPE_P (functype))
 	return error_mark_node;
 
-      /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
+      /* Under C++11 [12.8/32 class.copy], a returned lvalue is sometimes
 	 treated as an rvalue for the purposes of overload resolution to
 	 favor move constructors over copy constructors.
 
@@ -8618,8 +8618,6 @@ check_return_expr (tree retval, bool *no_warning)
 	      || TREE_CODE (retval) == PARM_DECL)
 	  && DECL_CONTEXT (retval) == current_function_decl
 	  && !TREE_STATIC (retval)
-	  && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
-			  (TYPE_MAIN_VARIANT (functype)))
 	  /* This is only interesting for class type.  */
 	  && CLASS_TYPE_P (functype))
 	flags = flags | LOOKUP_PREFER_RVALUE;

gcc/testsuite/ChangeLog

+2014-06-28  Jonathan Wakely  <jwakely@redhat.com>
+
+	* g++.dg/cpp0x/elision_conv.C: New.
+
 2014-06-27  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	* gfortran.dg/nint_2.f90: Don't XFAIL for powerpc64le-*-linux*.

gcc/testsuite/g++.dg/cpp0x/elision_conv.C

+// Core 1579 return by converting move constructor
+// PR c++/58051
+// { dg-do compile { target c++11 } }
+
+struct A {
+  A() = default;
+  A(A&&) = default;
+};
+
+struct B {
+  B(A) { }
+};
+
+B f()
+{
+  A a;
+  return a;
+}