re PR c++/52824 ([C++11] expanding variadic template arguments into non-variadic template)

	PR c++/52824
	* pt.c (any_pack_expanson_args_p): New.
	(coerce_template_parms): Use it.

From-SVN: r186434

gcc/cp/ChangeLog

 2012-04-13  Jason Merrill  <jason@redhat.com>
 
+	PR c++/52824
+	* pt.c (any_pack_expanson_args_p): New.
+	(coerce_template_parms): Use it.
+
 	PR c++/52905
 	* call.c (joust): Handle comparing list and non-list ctors.
 

gcc/cp/pt.c

@@ -6725,6 +6725,20 @@ coerce_template_parameter_pack (tree parms,
   return argument_pack;
 }
 
+/* Returns true if the template argument vector ARGS contains
+   any pack expansions, false otherwise.  */
+
+static bool
+any_pack_expanson_args_p (tree args)
+{
+  int i;
+  if (args)
+    for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
+      if (PACK_EXPANSION_P (TREE_VEC_ELT (args, i)))
+	return true;
+  return false;
+}
+
 /* Convert all template arguments to their appropriate types, and
    return a vector containing the innermost resulting template
    arguments.  If any error occurs, return error_mark_node. Error and
@@ -6790,6 +6804,7 @@ coerce_template_parms (tree parms,
   if ((nargs > nparms && !variadic_p)
       || (nargs < nparms - variadic_p
 	  && require_all_args
+	  && !any_pack_expanson_args_p (inner_args)
 	  && (!use_default_args
 	      || (TREE_VEC_ELT (parms, nargs) != error_mark_node
                   && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))

gcc/testsuite/ChangeLog

 2012-04-13  Jason Merrill  <jason@redhat.com>
 
+	PR c++/52824
+	* g++.dg/cpp0x/variadic123.C: New.
+	* g++.dg/cpp0x/alias-decl-15.C: Remove dg-errors.
+
 	PR c++/52905
 	* g++.dg/cpp0x/initlist-ctor1.C: New.
 

gcc/testsuite/g++.dg/cpp0x/alias-decl-15.C

@@ -2,7 +2,7 @@
 // { dg-options "-std=c++0x" }
 
 template<class U, class V> //#1
-struct foo {}; // { dg-error "provided for|foo" }
+struct foo {};
 
 template<class U, class V=char>
 struct P {};
@@ -10,8 +10,8 @@ struct P {};
 template<template<class... U> class... TT>
 struct bar {
     template<class... Args>
-    using mem = P<TT<Args...>...>;//#2 { dg-error "wrong number of|arguments" }
+    using mem = P<TT<Args...>...>;//#2
 };
 
-bar<foo>::mem<int, char> b;//#3 { dg-error "invalid type" }
+bar<foo>::mem<int, char> b;//#3
 

gcc/testsuite/g++.dg/cpp0x/variadic123.C

+// PR c++/52824
+// { dg-do compile { target c++11 } }
+
+template<typename G, typename H>
+struct foo
+{};
+
+template<typename... G>
+struct bar : foo<G...>
+{};
+
+int main() {
+  bar<int, float> f;
+}