From 2a28e76a78ec4f3bb1219c4ba5795f86dccb43cd Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Fri, 9 Nov 2012 11:14:48 -0500
Subject: [PATCH] re PR c++/54859 (constexpr in template alias rejected as
 non-constant)

	PR c++/54859
	* pt.c (check_instantiated_arg): Don't complain about dependent args.

From-SVN: r193368
---
 gcc/cp/ChangeLog                           |  3 +++
 gcc/cp/pt.c                                |  2 ++
 gcc/testsuite/ChangeLog                    |  3 +++
 gcc/testsuite/g++.dg/cpp0x/alias-decl-25.C | 10 ++++++++++
 4 files changed, 18 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/alias-decl-25.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 4d6d954db1f..59167be0e23 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2012-11-09  Jason Merrill  <jason@redhat.com>
 
+	PR c++/54859
+	* pt.c (check_instantiated_arg): Don't complain about dependent args.
+
 	* tree.c (cxx_attribute_table): Add abi_tag attribute.
 	(check_abi_tag_redeclaration, handle_abi_tag_attribute): New.
 	* class.c (find_abi_tags_r, check_abi_tags): New.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 1ff1c73b90d..50d12b08348 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -14362,6 +14362,8 @@ tsubst_copy_and_build (tree t,
 static bool
 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
 {
+  if (dependent_template_arg_p (t))
+    return false;
   if (ARGUMENT_PACK_P (t))
     {
       tree vec = ARGUMENT_PACK_ARGS (t);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 608e017943c..e8883134138 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2012-11-09  Jason Merrill  <jason@redhat.com>
 
+	PR c++/54859
+	* g++.dg/cpp0x/alias-decl-25.C: New.
+
 	* g++.dg/abi/abi-tag1.C: New.
 	* g++.dg/abi/abi-tag2.C: New.
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-25.C b/gcc/testsuite/g++.dg/cpp0x/alias-decl-25.C
new file mode 100644
index 00000000000..e72bd350912
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-25.C
@@ -0,0 +1,10 @@
+// PR c++/54859
+// { dg-options -std=c++11 }
+
+template<unsigned N>
+  using Num = int;
+
+template<typename... Types>
+  using Count = Num<sizeof...(Types)>;
+
+Count<int, char, void> i;