PR32673: Don't wrap parameter packs in SubstTemplateTypeParmPackType nodes when forming implicit deduction guides.

Doing so thwarts template type deduction. Instead, substitute the pack directly
by picking "slice 0" of the resulting expansion.

llvm-svn: 300805

1 files changed, 35 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/cxx1z-class-template-argument-deduction.cpp b/clang/test/SemaCXX/cxx1z-class-template-argument-deduction.cpp
index d6374e4ce90..5de228ad285 100644
--- a/clang/test/SemaCXX/cxx1z-class-template-argument-deduction.cpp
+++ b/clang/test/SemaCXX/cxx1z-class-template-argument-deduction.cpp
@@ -213,3 +213,38 @@ namespace transform_params {
   };
   D d(Y<0, 1, 2>{});
 }
+
+namespace variadic {
+  int arr3[3], arr4[4];
+
+  // PR32673
+  template<typename T> struct A {
+    template<typename ...U> A(T, U...);
+  };
+  A a(1, 2, 3);
+
+  template<typename T> struct B {
+    template<int ...N> B(T, int (&...r)[N]);
+  };
+  B b(1, arr3, arr4);
+
+  template<typename T> struct C {
+    template<template<typename> typename ...U> C(T, U<int>...);
+  };
+  C c(1, a, b);
+
+  template<typename ...U> struct X {
+    template<typename T> X(T, U...);
+  };
+  X x(1, 2, 3);
+
+  template<int ...N> struct Y {
+    template<typename T> Y(T, int (&...r)[N]);
+  };
+  Y y(1, arr3, arr4);
+
+  template<template<typename> typename ...U> struct Z {
+    template<typename T> Z(T, U<int>...);
+  };
+  Z z(1, a, b);
+}