From 4185fb7350876f0012455c3dd159f80494081686 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Fri, 29 Mar 2013 14:59:09 -0400
Subject: [PATCH] re PR c++/56774 (G++ 4.8 reverses variadic template types
 during unpacking)

	PR c++/56774
	PR c++/35722
	* pt.c (unify_pack_expansion): Fix indexing.

From-SVN: r197244
---
 gcc/cp/ChangeLog                                |  6 ++++++
 gcc/cp/pt.c                                     |  4 ++--
 gcc/testsuite/g++.dg/cpp0x/variadic-explicit2.C | 14 ++++++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/variadic-explicit2.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 224c5a2fe2e..6686bdcbecb 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2013-03-29  Jason Merrill  <jason@redhat.com>
+
+	PR c++/56774
+	PR c++/35722
+	* pt.c (unify_pack_expansion): Fix indexing.
+
 2013-03-29  Gabriel Dos Reis  <gdr@integrable-solutions.net>
 
 	* call.c (build_java_interface_fn_ref): Likewise.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 8468a84b285..4ef4ede1621 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -16213,10 +16213,10 @@ unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
           arg = NULL_TREE;
           if (TREE_VALUE (pack)
               && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
-              && (i < TREE_VEC_LENGTH (pargs)))
+              && (i - start < TREE_VEC_LENGTH (pargs)))
             {
               any_explicit = true;
-              arg = TREE_VEC_ELT (pargs, i);
+              arg = TREE_VEC_ELT (pargs, i - start);
             }
           TMPL_ARG (targs, level, idx) = arg;
         }
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-explicit2.C b/gcc/testsuite/g++.dg/cpp0x/variadic-explicit2.C
new file mode 100644
index 00000000000..4a80745293a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-explicit2.C
@@ -0,0 +1,14 @@
+// PR c++/56774
+// { dg-require-effective-target c++11 }
+
+template <class ... Args>
+struct mytype {};
+
+template <class T, class ... Args>
+void something( mytype<T, Args...> )
+{ }
+
+int main()
+{
+  something<int, char, bool>( mytype<int, char, bool>() );
+}