From: Jason Merrill <jason@redhat.com>
Date: Wed, 7 Oct 2009 18:56:39 +0000 (-0400)
Subject: re PR c++/39863 ([c++0x] variadic templates : wrong error "mismatched argument pack... 
X-Git-Tag: releases/gcc-4.5.0~3053
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f484a91ab45ed2eeeb4d87b454e14578cc506428;p=thirdparty%2Fgcc.git

re PR c++/39863 ([c++0x] variadic templates : wrong error "mismatched argument pack lengths")

	PR c++/39863
	* pt.c (tsubst_pack_expansion): Don't do anything now if we
	have incomplete packs of different lengths.

From-SVN: r152537
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index bb4ec8d5bc2e..cc6fa63515b0 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2009-10-07  Jason Merrill  <jason@redhat.com>
 
+	PR c++/39863
+	* pt.c (tsubst_pack_expansion): Don't do anything now if we
+	have incomplete packs of different lengths.
+
 	PR c++/41038
 	* tree.c (build_qualified_name): Call convert_from_reference.
 
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 6b98956d6e61..9ef3f79a599a 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -7944,6 +7944,10 @@ tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
             }
           else if (len != my_len)
             {
+	      if (incomplete)
+		/* We got explicit args for some packs but not others;
+		   do nothing now and try again after deduction.  */
+		return t;
               if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
                 error ("mismatched argument pack lengths while expanding "
                        "%<%T%>",
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a7b7a16508a0..fe14298215eb 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-10-07  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/cpp0x/variadic95.C: New.
+
 2009-10-07  Jason Merrill  <jason@redhat.com>
 
 	* g++.dg/template/scope3.C: New.
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic95.C b/gcc/testsuite/g++.dg/cpp0x/variadic95.C
new file mode 100644
index 000000000000..ebb04ebc10b8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic95.C
@@ -0,0 +1,17 @@
+// PR c++/39863
+// { dg-options -std=c++0x }
+
+template <typename... T>
+struct A {};
+
+template <typename T, typename U>
+struct S {};
+
+template <typename... T, typename... U>
+A< S<T, U>... > f(U... u)
+{ return A< S<T, U>... >(); }
+
+int main()
+{
+  f<int>(0.0);
+}