From: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 3 Mar 2016 22:43:09 +0000 (+0000)
Subject: 	PR c++/51406
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b0531ab4e2581d76137c956e486c3a4d2d75a223;p=thirdparty%2Fgcc.git

	PR c++/51406

	* typeck.c (build_static_cast_1): Avoid folding back to lvalue.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@233946 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index f2c9cd25c1bb..a7ae483c33d5 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2016-03-03  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51406
+	* typeck.c (build_static_cast_1): Avoid folding back to lvalue.
+
 	PR c++/67364
 	* constexpr.c (cxx_eval_component_reference): Just return an empty
 	CONSTRUCTOR for an empty class.
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 51458798c5ba..20f0afc74d7a 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -6704,11 +6704,7 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
 	  tree lref = cp_build_reference_type (TREE_TYPE (type), false);
 	  result = (perform_direct_initialization_if_possible
 		    (lref, expr, c_cast_p, complain));
-	  result = cp_fold_convert (type, result);
-	  /* Make sure we don't fold back down to a named rvalue reference,
-	     because that would be an lvalue.  */
-	  if (DECL_P (result))
-	    result = build1 (NON_LVALUE_EXPR, type, result);
+	  result = build1 (NON_LVALUE_EXPR, type, result);
 	  return convert_from_reference (result);
 	}
       else
diff --git a/gcc/testsuite/g++.dg/cpp0x/rv-cast5.C b/gcc/testsuite/g++.dg/cpp0x/rv-cast5.C
new file mode 100644
index 000000000000..c2473e266b64
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/rv-cast5.C
@@ -0,0 +1,12 @@
+// { dg-do compile { target c++11 } }
+
+template <typename T>
+struct hold {
+  T value;
+  constexpr T&& operator()() && { return static_cast<T&&>(value); }
+};
+
+int main()
+{
+  hold<bool&&>{42}();
+}