libcxx/test/std/experimental/utilities/meta/meta.detect/is_detected_exact.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11
  10 // <experimental/type_traits>
  11
  12 #include <experimental/type_traits>
  13 #include <string>
  14
  15 #include "test_macros.h"
  16
  17 namespace ex = std::experimental;
  18
  19 template <typename T>
  20   using callFoo = decltype(std::declval<T&>().Foo());
  21
  22 struct yesFoo {
  23     int Foo() { return 0; }
  24 };
  25
  26 struct noFoo {
  27 };
  28
  29 struct wrongFoo {
  30     std::string Foo() { return ""; }
  31 };
  32
  33 struct convertibleFoo {
  34     long Foo() { return 0; }
  35 };
  36
  37 template <typename T, bool b>
  38 void test() {
  39     static_assert( b == ex::is_detected_exact  <int, callFoo, T>::value, "" );
  40     static_assert( b == ex::is_detected_exact_v<int, callFoo, T>, "" );
  41 }
  42
  43 int main(int, char**) {
  44     test<yesFoo, true>();
  45     test<noFoo, false>();
  46     test<wrongFoo, false>();
  47     test<convertibleFoo, false>();
  48
  49   return 0;
  50 }