re PR c++/48617 ([C++0x] Problem with non-type template parameters and decltype)

	PR c++/48617
	* pt.c (invalid_nontype_parm_type_p): Allow DECLTYPE_TYPE.

From-SVN: r174070

gcc/cp/ChangeLog

+2011-05-23  Jason Merrill  <jason@redhat.com>
+
+	PR c++/48617
+	* pt.c (invalid_nontype_parm_type_p): Allow DECLTYPE_TYPE.
+
 2011-05-23  Nathan Froyd  <froydnj@codesourcery.com>
 
 	* call.c (build_over_call): Tweak call to check_function_arguments.

gcc/cp/pt.c

@@ -18089,6 +18089,8 @@ invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
     return 0;
   else if (TREE_CODE (type) == TYPENAME_TYPE)
     return 0;
+  else if (TREE_CODE (type) == DECLTYPE_TYPE)
+    return 0;
 
   if (complain & tf_error)
     error ("%q#T is not a valid type for a template constant parameter", type);

gcc/testsuite/ChangeLog

+2011-05-23  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/cpp0x/decltype27.C: New.
+
 2011-05-23  Richard Guenther  <rguenther@suse.de>
 
 	* gcc.dg/tree-ssa/forwprop-11.c: Adjust and un-XFAIL.

gcc/testsuite/g++.dg/cpp0x/decltype27.C

+// PR c++/48617
+// { dg-options -std=c++0x }
+
+template<class T, decltype(T())> // #
+struct A {};
+
+A<int, 0> a;
+
+int main() {}