re PR c++/40595 ([C++0x] ICE trying to use sfinae with variadic template pack expansion)

	PR c++/40595
	* pt.c (tsubst_pack_expansion): Handle unexpanded packs in an
	EXPR_PACK_EXPANSION.

From-SVN: r149117

gcc/cp/ChangeLog

+2009-06-30  Jason Merrill  <jason@redhat.com>
+
+	PR c++/40595
+	* pt.c (tsubst_pack_expansion): Handle unexpanded packs in an
+	EXPR_PACK_EXPANSION.
+
 2009-06-29  Jason Merrill  <jason@redhat.com>
 
 	PR c++/40274

gcc/cp/pt.c

@@ -7630,8 +7630,15 @@ tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
      and return a PACK_EXPANSION_*. The caller will need to deal with
      that.  */
   if (unsubstituted_packs)
-    return make_pack_expansion (tsubst (pattern, args, complain, 
-					in_decl));
+    {
+      tree new_pat;
+      if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
+	new_pat = tsubst_expr (pattern, args, complain, in_decl,
+			       /*integral_constant_expression_p=*/false);
+      else
+	new_pat = tsubst (pattern, args, complain, in_decl);
+      return make_pack_expansion (new_pat);
+    }
 
   /* We could not find any argument packs that work.  */
   if (len < 0)

gcc/testsuite/ChangeLog

+2009-06-30  Jason Merrill  <jason@redhat.com>
+
+	PR c++/40595
+	* g++.dg/cpp0x/variadic94.C: New.
+
 2009-06-30  Richard Sandiford  <r.sandiford@uk.ibm.com>
 
 	* lib/gcc-defs.exp (gcc-set-multilib-library-path): Delete.

gcc/testsuite/g++.dg/cpp0x/variadic94.C

+// PR c++/40595
+// { dg-options "-std=c++0x" }
+
+template<int N>
+struct S
+{
+    typedef int type;
+};
+
+template<typename T>
+struct Get
+{
+    static T get();
+};
+
+template<typename F>
+struct B
+{
+    template<typename ... Args>
+        typename S<sizeof( Get<F>::get() (Get<Args>::get() ...) )>::type
+        f(Args&& ... a);
+};
+
+struct X
+{
+    bool operator()(int) const;
+};
+
+int main()
+{
+    B<X> b;
+    b.f(1);
+}