PR c++/52343 - error with alias template as template template argument

In the example accompanying this patch, check_instantiated_arg tries
to ensure that a non-type template argument should be a constant if it
has integral or enumeration type.

The problem is that an alias template which type-id is, e.g, an
integer, looks like an argument that has integral/enumeration type:
its TREE_TYPE is an integer type.  So check_instantiated_arg
mistenkaly barks that this integral non-type argument is not a
constant.

Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.

gcc/cp/

	PR c++/52343
	* pt.c (check_instantiated_arg): Allow type template arguments.

gcc/testsuite/

	PR c++/52343
	* g++.dg/cpp0x/alias-decl-29.C: New test.

From-SVN: r194960

gcc/cp/ChangeLog

+2013-01-04  Dodji Seketeli  <dodji@redhat.com>
+
+	PR c++/52343
+	* pt.c (check_instantiated_arg): Allow type template arguments.
+
 2013-01-04  Jason Merrill  <jason@redhat.com>
 
 	PR c++/55877

gcc/cp/pt.c

@@ -14419,6 +14419,9 @@ check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
 	  return true;
 	}
     }
+  /* Class template and alias template arguments should be OK.  */
+  else if (DECL_TYPE_TEMPLATE_P (t))
+    ;
   /* A non-type argument of integral or enumerated type must be a
      constant.  */
   else if (TREE_TYPE (t)

gcc/testsuite/ChangeLog

+2013-01-04  Dodji Seketeli  <dodji@redhat.com>
+
+	PR c++/52343
+	* g++.dg/cpp0x/alias-decl-29.C: New test.
+
 2013-01-06  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/PR53876

gcc/testsuite/g++.dg/cpp0x/alias-decl-29.C

+// Origin: PR c++/52343
+// { dg-do compile { target c++11 } }
+
+template<typename>
+using A = int;
+
+template<template<class> class>
+struct B {};
+
+B<A> b;