From 70ba248488aed2c9f17d16086f3783ddd95c9244 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Thu, 5 Jul 2012 17:24:33 -0400
Subject: [PATCH] re PR c++/53039 (including <functional> breaks
std::is_convertible with template-pack expansion)
PR c++/53039
* pt.c (arg_from_parm_pack_p): Go back to using same_type_p or
cp_tree_equal.
From-SVN: r189305
---
gcc/cp/ChangeLog | 4 ++++
gcc/cp/pt.c | 35 +++++++----------------------------
2 files changed, 11 insertions(+), 28 deletions(-)
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index f4ed6fb3ea52..4d1fc5ce27c1 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
2012-07-05 Jason Merrill <jason@redhat.com>
+ PR c++/53039
+ * pt.c (arg_from_parm_pack_p): Go back to using same_type_p or
+ cp_tree_equal.
+
* cp-tree.h (TEMPLATE_PARM_NUM_SIBLINGS): Remove.
(struct template_parm_index_s): Remove num_siblings.
* pt.c (fixup_template_parms, fixup_template_parm_index): Remove.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index e07a36242b75..df5d1f68b862 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -3760,34 +3760,13 @@ arg_from_parm_pack_p (tree arg_pack, tree parm_pack)
{
tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
tree pattern = PACK_EXPANSION_PATTERN (expansion);
- /* So we have an argument_pack<P...>. We want to test if P
- is actually PARM_PACK. We will not use cp_tree_equal to
- test P and PARM_PACK because during type fixup (by
- fixup_template_parm) P can be a pre-fixup version of a
- type and PARM_PACK be its post-fixup version.
- cp_tree_equal would consider them as different even
- though we would want to consider them compatible for our
- precise purpose here.
-
- Thus we are going to consider that P and PARM_PACK are
- compatible if they have the same DECL. */
- if ((/* If ARG_PACK is a type parameter pack named by the
- same DECL as parm_pack ... */
- (TYPE_P (pattern)
- && TYPE_P (parm_pack)
- && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
- /* ... or if PARM_PACK is a non-type parameter named by the
- same DECL as ARG_PACK. Note that PARM_PACK being a
- non-type parameter means it's either a PARM_DECL or a
- TEMPLATE_PARM_INDEX. */
- || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
- && ((TREE_CODE (parm_pack) == PARM_DECL
- && (TEMPLATE_PARM_DECL (pattern)
- == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
- || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX
- && (TEMPLATE_PARM_DECL (pattern)
- == TEMPLATE_PARM_DECL (parm_pack))))))
- && template_parameter_pack_p (pattern))
+ if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
+ || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
+ /* The argument pack that the parameter maps to is just an
+ expansion of the parameter itself, such as one would
+ find in the implicit typedef of a class inside the
+ class itself. Consider this parameter "unsubstituted",
+ so that we will maintain the outer pack expansion. */
return true;
}
return false;
--
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