1 files changed, 149 insertions, 0 deletions
diff --git a/test/CXX/expr/expr.prim/expr.prim.id/p3.cpp b/test/CXX/expr/expr.prim/expr.prim.id/p3.cpp
new file mode 100644
index 0000000000..dd3f0c0e3d
--- /dev/null
+++ b/test/CXX/expr/expr.prim/expr.prim.id/p3.cpp
@@ -0,0 +1,149 @@
+// RUN:  %clang_cc1 -std=c++2a -verify -triple x86_64-linux-gnu %s
+
+template<typename T> concept C1 = true; // expected-note{{template is declared here}}
+static_assert(C1<int>);
+static_assert(C1);
+// expected-error@-1{{use of concept 'C1' requires template arguments}}
+
+template<typename T> concept C2 = sizeof(T) == 4;
+static_assert(C2<int>);
+static_assert(!C2<long long int>);
+static_assert(C2<char[4]>);
+static_assert(!C2<char[5]>);
+
+template<typename T> concept C3 = sizeof(*T{}) == 4;
+static_assert(C3<int*>);
+static_assert(!C3<long long int>);
+
+struct A {
+  static constexpr int add(int a, int b) {
+    return a + b;
+  }
+};
+struct B {
+  static int add(int a, int b) { // expected-note{{declared here}}
+    return a + b;
+  }
+};
+template<typename U>
+concept C4 = U::add(1, 2) == 3;
+// expected-error@-1{{substitution into constraint expression resulted in a non-constant expression}}
+// expected-note@-2{{non-constexpr function 'add' cannot be used in a constant expression}}
+static_assert(C4<A>);
+static_assert(!C4<B>); // expected-note {{while checking the satisfaction of concept 'C4<B>' requested here}}
+
+template<typename T, typename U>
+constexpr bool is_same_v = false;
+
+template<typename T>
+constexpr bool is_same_v<T, T> = true;
+
+template<typename T, typename U>
+concept Same = is_same_v<T, U>;
+
+static_assert(Same<int, int>);
+static_assert(Same<int, decltype(1)>);
+static_assert(!Same<int, unsigned int>);
+static_assert(!Same<A, B>);
+static_assert(Same<A, A>);
+
+static_assert(Same<bool, decltype(C1<int>)>);
+static_assert(Same<bool, decltype(C2<int>)>);
+static_assert(Same<bool, decltype(C3<int*>)>);
+static_assert(Same<bool, decltype(C4<A>)>);
+
+template<typename T> concept C5 = T{}; // expected-error {{atomic constraint must be of type 'bool' (found 'int')}}
+constexpr bool x = C5<int>; // expected-note {{while checking the satisfaction of concept 'C5<int>' requested here}}
+
+template<int x>
+concept IsEven = (x % 2) == 0;
+
+static_assert(IsEven<20>);
+static_assert(!IsEven<11>);
+
+template<template<typename T> typename P>
+concept IsTypePredicate = is_same_v<decltype(P<bool>::value), const bool>
+                          && is_same_v<decltype(P<int>::value), const bool>
+                          && is_same_v<decltype(P<long long>::value), const bool>;
+
+template<typename T> struct T1 {};
+template<typename T> struct T2 { static constexpr bool value = sizeof(T) == 2; };
+
+static_assert(IsTypePredicate<T2>);
+static_assert(!IsTypePredicate<T1>);
+
+namespace piecewise_substitution {
+  template <typename T>
+  concept True = true;
+
+  template <typename T>
+  concept A = True<T> || T::value;
+
+  template <typename T>
+  concept B = (True<T> || T::value);
+
+  template <typename T>
+  concept C = !True<T> && T::value || true;
+
+  template <typename T>
+  concept D = (!True<T> && T::value) || true;
+
+  template <typename T>
+  concept E = T::value || True<T>;
+
+  template <typename T>
+  concept F = (T::value || True<T>);
+
+  template <typename T>
+  concept G = T::value && !True<T> || true;
+
+  template <typename T>
+  concept H = (T::value && !True<T>) || true;
+
+  template <typename T>
+  concept I = T::value;
+
+  static_assert(A<int>);
+  static_assert(B<int>);
+  static_assert(C<int>);
+  static_assert(D<int>);
+  static_assert(E<int>);
+  static_assert(F<int>);
+  static_assert(G<int>);
+  static_assert(H<int>);
+  static_assert(!I<int>);
+}
+
+// Short ciruiting
+
+template<typename T> struct T3 { using type = typename T::type; };
+// expected-error@-1{{type 'char' cannot be used prior to '::' because it has no members}}
+// expected-error@-2{{type 'short' cannot be used prior to '::' because it has no members}}
+
+template<typename T>
+concept C6 = sizeof(T) == 1 && sizeof(typename T3<T>::type) == 1;
+// expected-note@-1{{while substituting template arguments into constraint expression here}}
+// expected-note@-2{{in instantiation of template class 'T3<char>' requested here}}
+
+template<typename T>
+concept C7 = sizeof(T) == 1 || sizeof(
+// expected-note@-1{{while substituting template arguments into constraint expression here}}
+    typename
+      T3<T>
+// expected-note@-1{{in instantiation of template class 'T3<short>' requested here}}
+        ::type) == 1;
+
+static_assert(!C6<short>);
+static_assert(!C6<char>); // expected-note{{while checking the satisfaction of concept 'C6<char>' requested here}}
+static_assert(C7<char>);
+static_assert(!C7<short>); // expected-note{{while checking the satisfaction of concept 'C7<short>' requested here}}
+
+// Make sure argument list is converted when instantiating a CSE.
+
+template<typename T, typename U = int>
+concept SameSize = sizeof(T) == sizeof(U);
+
+template<typename T>
+struct X { static constexpr bool a = SameSize<T>; };
+
+static_assert(X<unsigned>::a);