PR13136:

 * When substituting a reference to a non-type template parameter pack where the
   corresponding argument is a pack expansion, transform into an expression
   which contains an unexpanded parameter pack rather than into an expression
   which contains a pack expansion. This causes the SubstNonTypeTemplateParmExpr
   to be inside the PackExpansionExpr, rather than outside, so the expression
   still looks like a pack expansion and can be deduced.

 * Teach MarkUsedTemplateParameters that we can deduce a reference to a template
   parameter if it's wrapped in a SubstNonTypeTemplateParmExpr (such nodes are
   added during alias template substitution).

llvm-svn: 159922

1 files changed, 19 insertions, 0 deletions

diff --git a/clang/test/SemaTemplate/alias-templates.cpp b/clang/test/SemaTemplate/alias-templates.cpp
index a074bc4e1e6..cd796b8603d 100644
--- a/clang/test/SemaTemplate/alias-templates.cpp
+++ b/clang/test/SemaTemplate/alias-templates.cpp
@@ -109,3 +109,22 @@ namespace PR13243 {
   template<typename A, int I> void f(X<A>, Ci<I>) {}
   template void f(X<int>, C<0>);
 }
+
+namespace PR13136 {
+  template <typename T, T... Numbers>
+  struct NumberTuple { };
+
+  template <unsigned int... Numbers>
+  using MyNumberTuple = NumberTuple<unsigned int, Numbers...>;
+
+  template <typename U, unsigned int... Numbers>
+  void foo(U&&, MyNumberTuple<Numbers...>);
+
+  template <typename U, unsigned int... Numbers>
+  void bar(U&&, NumberTuple<unsigned int, Numbers...>);
+
+  int main() {
+    foo(1, NumberTuple<unsigned int, 0, 1>());
+    bar(1, NumberTuple<unsigned int, 0, 1>());
+  }
+}