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

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++98, c++03, c++11
// <experimental/type_traits>

#include <experimental/type_traits>
#include <string>

#include "test_macros.h"

namespace ex = std::experimental;

template <typename T>
  using callFoo = decltype(std::declval<T&>().Foo());

struct yesFoo {
    int Foo() { return 0; }
};

struct noFoo {
};

struct wrongFoo {
    std::string Foo() { return ""; }
};

struct convertibleFoo {
    long Foo() { return 0; }
};

template <typename T, bool b>
void test() {
    static_assert( b == ex::is_detected_exact  <int, callFoo, T>::value, "" );
    static_assert( b == ex::is_detected_exact_v<int, callFoo, T>, "" );
}

int main () {
    test<yesFoo, true>();
    test<noFoo, false>();
    test<wrongFoo, false>();
    test<convertibleFoo, false>();
}