Re: C++ PATCH for c++/59296 (rvalue object and lvalue ref-qualifier)

[Jason Merrill]

On 06/19/2014 12:12 AM, Jason Merrill wrote:

We were treating a const & member function like a normal const
reference, and binding an rvalue object argument to it.  But it doesn't
work that way.

In 4.9 we also need to set LOOKUP_NO_TEMP_BIND.




commit 48ca9803695872d984b0f4efa56f7f58987d0928
Author: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Wed Jun 18 22:13:51 2014 +0000

    	PR c++/59296
    	* call.c (add_function_candidate): Set LOOKUP_NO_RVAL_BIND
    	|LOOKUP_NO_TEMP_BIND for ref-qualifier handling.

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 2c3d4ac..fc65b97 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -1999,6 +1999,9 @@ add_function_candidate (struct z_candidate **candidates,
 		     object parameter has reference type.  */
 		  bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn));
 		  parmtype = cp_build_reference_type (parmtype, rv);
+		  /* Don't bind an rvalue to a const lvalue ref-qualifier.  */
+		  if (!rv)
+		    lflags |= LOOKUP_NO_RVAL_BIND|LOOKUP_NO_TEMP_BIND;
 		}
 	      else
 		{
diff --git a/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C b/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C
new file mode 100644
index 0000000..ca333c2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/ref-qual15.C
@@ -0,0 +1,13 @@
+// PR c++/59296
+// { dg-do compile { target c++11 } }
+
+struct Type
+{
+  void get() const& { }
+  void get() const&& { }
+};
+
+int main()
+{
+  Type{}.get();
+}