commit dcc37da352dd87c5f2f1f103c9794effa180e43d
Author: Jason Merrill <jason@redhat.com>
Date:   Fri Apr 8 18:55:21 2011 -0400

    	PR c++/48457, Core 1238
    	* call.c (reference_binding): Allow rvalue reference to bind to
    	function lvalue.
    	* tree.c (lvalue_kind): Functions are always lvalues.

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 096fbbc..4d03646 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -1521,8 +1521,10 @@ reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
 	   actually occurs.  */
 	conv->need_temporary_p = true;
 
-      /* Don't allow binding of lvalues to rvalue references.  */
+      /* Don't allow binding of lvalues (other than function lvalues) to
+	 rvalue references.  */
       if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
+	  && TREE_CODE (to) != FUNCTION_TYPE
           && !(flags & LOOKUP_PREFER_RVALUE))
 	conv->bad_p = true;
 
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 3594ae4..d6b6197 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -73,7 +73,9 @@ lvalue_kind (const_tree ref)
       if (TYPE_REF_IS_RVALUE (TREE_TYPE (ref))
 	  && TREE_CODE (ref) != PARM_DECL
 	  && TREE_CODE (ref) != VAR_DECL
-	  && TREE_CODE (ref) != COMPONENT_REF)
+	  && TREE_CODE (ref) != COMPONENT_REF
+	  /* Functions are always lvalues.  */
+	  && TREE_CODE (TREE_TYPE (TREE_TYPE (ref))) != FUNCTION_TYPE)
 	return clk_rvalueref;
 
       /* lvalue references and named rvalue references are lvalues.  */
diff --git a/gcc/testsuite/g++.dg/cpp0x/rv-func.C b/gcc/testsuite/g++.dg/cpp0x/rv-func.C
new file mode 100644
index 0000000..db14296
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/rv-func.C
@@ -0,0 +1,22 @@
+// PR c++/48457, Core 1238
+// { dg-options -std=c++0x }
+
+template<class T>
+T&& create();
+
+template<class T, class Arg>
+void test() {
+  T t(create<Arg>());
+  (void) t;
+}
+
+void f (void (&)());
+void f (void (&&)());
+
+int main() {
+  test<void(&)(), void()>();
+  test<void(&&)(), void()>();
+  // This call should choose the lvalue reference overload.
+  // { dg-final { scan-assembler-not "_Z1fOFvvE" } }
+  f(create<void()>());
+}
diff --git a/libstdc++-v3/testsuite/20_util/is_convertible/value.cc b/libstdc++-v3/testsuite/20_util/is_convertible/value.cc
index f6282a9..fc6007a 100644
--- a/libstdc++-v3/testsuite/20_util/is_convertible/value.cc
+++ b/libstdc++-v3/testsuite/20_util/is_convertible/value.cc
@@ -93,7 +93,7 @@ void test01()
 	                                     const volatile int&>(false)) );
   VERIFY( (test_relationship<is_convertible, volatile int,
 	                                     volatile int&>(false)) );
-  VERIFY( (test_relationship<is_convertible, int(int), int(&)(int)>(false)) );
+  VERIFY( (test_relationship<is_convertible, int(int), int(&)(int)>(true)) );
 
   VERIFY( (test_relationship<is_convertible, int&, ExplicitClass>(false)) );
   VERIFY( (test_relationship<is_convertible, void*, ExplicitClass>(false)) );