re PR c++/62659 (Regression in template argument substitution in 4.9+)

PR c++/62659
	* semantics.c (potential_constant_expression_1): Handle un-folded
	pointer to member constants.

From-SVN: r214974

gcc/cp/ChangeLog

@@ -1,3 +1,9 @@
+2014-09-05  Jason Merrill  <jason@redhat.com>
+
+	PR c++/62659
+	* semantics.c (potential_constant_expression_1): Handle un-folded
+	pointer to member constants.
+
 2014-09-04  Markus Trippelsdorf  <markus@trippelsdorf.de>
 
 	PR ipa/61659

gcc/cp/semantics.c

@@ -10348,6 +10348,11 @@ potential_constant_expression_1 (tree t, bool want_rval, tsubst_flags_t flags)
             designates an object with thread or automatic storage
             duration;  */
       t = TREE_OPERAND (t, 0);
+
+      if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t))
+	/* A pointer-to-member constant.  */
+	return true;
+
 #if 0
       /* FIXME adjust when issue 1197 is fully resolved.  For now don't do
          any checking here, as we might dereference the pointer later.  If

gcc/testsuite/g++.dg/template/ptrmem29.C

@@ -0,0 +1,10 @@
+// PR c++/62659
+
+struct D {
+  typedef int (D::*cont_func)();
+  template <cont_func> struct B;
+  template <cont_func cont_f> void wait(B<cont_f> ***);
+
+  int done();
+  template <bool> void fix() { wait<&D::done>(0); }
+};