Patchwork C++ PATCH for c++/52824 (pack expansion and fixed template parameters)

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Submitter Jason Merrill
Date April 13, 2012, 7:37 p.m.
Message ID <4F888094.502@redhat.com>
Download mbox | patch
Permalink /patch/152389/
State New
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Comments

Jason Merrill - April 13, 2012, 7:37 p.m.
One case that I missed in my patch for PR 35722.

Tested x86_64-pc-linux-gnu, applying to trunk and 4.7.

Patch

commit 9fa7eea3608b19b53cc2f3c9a8195cf811b02d84
Author: Jason Merrill <jason@redhat.com>
Date:   Fri Apr 13 13:37:26 2012 -0400

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

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index ee38254..07a2cc0 100644
--- a/gcc/cp/pt.c
+++ b/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))))))
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-15.C b/gcc/testsuite/g++.dg/cpp0x/alias-decl-15.C
index 2bc9b11..b23e402 100644
--- a/gcc/testsuite/g++.dg/cpp0x/alias-decl-15.C
+++ b/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
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic123.C b/gcc/testsuite/g++.dg/cpp0x/variadic123.C
new file mode 100644
index 0000000..f0ab9fc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic123.C
@@ -0,0 +1,14 @@ 
+// 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;
+}