2 files changed, 79 insertions, 0 deletions
diff --git a/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp b/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp
index 95fe35b4591..153d4a56bea 100644
--- a/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp
+++ b/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp
@@ -16,3 +16,54 @@ template<typename T> requires Bar2<T> struct S2 { };
 template<typename T> requires Bar2<T> && true struct S2<T> { };
 // expected-error@-1{{class template partial specialization is not more specialized than the primary template}}
 // expected-note@-2{{while calculating associated constraint of template 'S2' here}}
+
+namespace type_pack {
+  template<typename... Args>
+  concept C1 = ((sizeof(Args) >= 0) && ...);
+
+  template<typename A, typename... B>
+  concept C2 = C1<A, B...>;
+
+  template<typename T>
+  constexpr void foo() requires C2<T, char, T> { }
+
+  template<typename T>
+  constexpr void foo() requires C1<T, char, T> && true { }
+
+  static_assert((foo<int>(), true));
+}
+
+namespace template_pack {
+  template<typename T> struct S1 {};
+  template<typename T> struct S2 {};
+
+  template<template<typename> typename... Args>
+  concept C1 = ((sizeof(Args<int>) >= 0) && ...);
+
+  template<template<typename> typename A, template<typename> typename... B>
+  concept C2 = C1<A, B...>;
+
+  template<template<typename> typename T>
+  constexpr void foo() requires C2<T, S1, T> { }
+
+  template<template<typename> typename T>
+  constexpr void foo() requires C1<T, S1, T> && true { }
+
+  static_assert((foo<S2>(), true));
+}
+
+namespace non_type_pack {
+  template<int... Args>
+  concept C1 = ((Args >= 0) && ...);
+
+  template<int A, int... B>
+  concept C2 = C1<A, B...>;
+
+  template<int T>
+  constexpr void foo() requires C2<T, 2, T> { }
+
+  template<int T>
+  constexpr void foo() requires C1<T, 2, T> && true { }
+
+  static_assert((foo<1>(), true));
+}
diff --git a/clang/test/SemaTemplate/instantiate-template-argument.cpp b/clang/test/SemaTemplate/instantiate-template-argument.cpp
new file mode 100644
index 00000000000..43d5d00c8cb
--- /dev/null
+++ b/clang/test/SemaTemplate/instantiate-template-argument.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify
+
+template<auto T, decltype(T) U>
+concept C1 = sizeof(U) >= 4;
+// sizeof(U) >= 4 [U = U (decltype(T))]
+
+template<typename Y, char V>
+concept C2 = C1<Y{}, V>;
+// sizeof(U) >= 4 [U = V (decltype(Y{}))]
+
+template<char W>
+constexpr int foo() requires C2<int, W> { return 1; }
+// sizeof(U) >= 4 [U = W (decltype(int{}))]
+
+template<char X>
+// expected-note@+1{{candidate function}}
+constexpr int foo() requires C1<1, X> && true { return 2; }
+// sizeof(U) >= 4 [U = X (decltype(1))]
+
+static_assert(foo<'a'>() == 2);
+
+template<char Z>
+// expected-note@+1{{candidate function}}
+constexpr int foo() requires C2<long long, Z> && true { return 3; }
+// sizeof(U) >= 4 [U = Z (decltype(long long{}))]
+
+static_assert(foo<'a'>() == 3);
+// expected-error@-1{{call to 'foo' is ambiguous}}
+\ No newline at end of file