re PR c++/65977 (Constexpr should be allowed in declaration of friend template specialization)

/cp
2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/65977
	* decl.c (grokfndecl): Allow constexpr declarations of friend
	template specializations.

/testsuite
2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/65977
	* g++.dg/cpp0x/constexpr-friend-3.C: New.
	* g++.dg/cpp0x/constexpr-friend-2.C: Adjust.

From-SVN: r225148

gcc/cp/ChangeLog

+2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/65977
+	* decl.c (grokfndecl): Allow constexpr declarations of friend
+	template specializations.
+
 2015-06-29  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	PR fortran/66605

gcc/cp/decl.c

@@ -7738,15 +7738,12 @@ grokfndecl (tree ctype,
 	    }
 
 	  if (inlinep & 1)
-	    error ("%<inline%> is not allowed in declaration of friend "
-		   "template specialization %qD",
-		   decl);
-	  if (inlinep & 2)
-	    error ("%<constexpr%> is not allowed in declaration of friend "
-		   "template specialization %qD",
-		   decl);
-	  if (inlinep)
-	    return NULL_TREE;
+	    {
+	      error ("%<inline%> is not allowed in declaration of friend "
+		     "template specialization %qD",
+		     decl);
+	      return NULL_TREE;
+	    }
 	}
     }
 

gcc/testsuite/ChangeLog

+2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/65977
+	* g++.dg/cpp0x/constexpr-friend-3.C: New.
+	* g++.dg/cpp0x/constexpr-friend-2.C: Adjust.
+
 2015-06-29  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	PR fortran/66605

gcc/testsuite/g++.dg/cpp0x/constexpr-friend-2.C

@@ -3,5 +3,5 @@
 template<typename T> void f(T);
 
 template <class T> class A {
-  friend constexpr void f<>(int);  // { dg-error "'constexpr' is not allowed" }
+  friend constexpr void f<>(int);
 };

gcc/testsuite/g++.dg/cpp0x/constexpr-friend-3.C

+// PR c++/65977
+// { dg-do compile { target c++11 } }
+
+template<__SIZE_TYPE__>
+class bitset;
+
+template<__SIZE_TYPE__ N>
+constexpr bool operator==(const bitset<N>&, const bitset<N>&) noexcept;
+
+template<__SIZE_TYPE__ N>
+class bitset
+{
+  friend constexpr bool operator== <>(const bitset<N>&,
+				      const bitset<N>&) noexcept;
+};
+
+template<__SIZE_TYPE__ N>
+constexpr bool operator==(const bitset<N>&, const bitset<N>&) noexcept
+{
+  return true;
+}