Implement partial ordering of class template partial specializations

and function templates that contain variadic templates. This involves
three small-ish changes:

  (1) When transforming a pack expansion, if the transformed argument
  still contains unexpanded parameter packs, build a pack
  expansion. This can happen during the substitution that occurs into
  class template partial specialiation template arguments during
  partial ordering. 
 
  (2) When performing template argument deduction where the argument
  is a pack expansion, match against the pattern of that pack
  expansion.

  (3) When performing template argument deduction against a non-pack
  parameter, or a non-expansion template argument, deduction fails if
  the argument itself is a pack expansion (C++0x
  [temp.deduct.type]p22).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123279 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 27 insertions, 0 deletions

diff --git a/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp b/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp
new file mode 100644
index 0000000000..116810082d
--- /dev/null
+++ b/test/CXX/temp/temp.fct.spec/temp.deduct/temp.deduct.partial/p12.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -std=c++0x -fsyntax-only -verify %s
+
+// Note: Partial ordering of function templates containing template
+// parameter packs is independent of the number of deduced arguments
+// for those template parameter packs.
+template<class ...> struct Tuple { }; 
+template<class ... Types> int &g(Tuple<Types ...>); // #1 
+template<class T1, class ... Types> float &g(Tuple<T1, Types ...>); // #2
+template<class T1, class ... Types> double &g(Tuple<T1, Types& ...>); // #3
+
+void test_g() {
+  int &ir1 = g(Tuple<>()); 
+  float &fr1 = g(Tuple<int, float>()); 
+  double &dr1 = g(Tuple<int, float&>()); 
+  double &dr2 = g(Tuple<int>());
+}
+
+template<class ... Types> int &h(int (*)(Types ...)); // #1 
+template<class T1, class ... Types> float &h(int (*)(T1, Types ...)); // #2
+template<class T1, class ... Types> double &h(int (*)(T1, Types& ...)); // #3
+
+void test_h() {
+  int &ir1 = h((int(*)())0); 
+  float &fr1 = h((int(*)(int, float))0);
+  double &dr1 = h((int(*)(int, float&))0);
+  double &dr2 = h((int(*)(int))0);
+}