Files
callable_traits/test/arg_at_constraints.cpp
2016-12-10 18:25:20 -06:00

57 lines
1.4 KiB
C++

/*
Copyright Barrett Adair 2016
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http ://boost.org/LICENSE_1_0.txt)
*/
#include <boost/callable_traits/arg_at.hpp>
#include "test.hpp"
struct foo;
template<std::size_t I, typename T>
struct is_substitution_failure_arg_at {
template<typename>
static auto test(...) -> std::true_type;
template<typename U,
typename std::remove_reference<arg_at_t<I, U>>::type* = nullptr>
static auto test(int) -> std::false_type;
static constexpr bool value = decltype(test<T>(0))::value;
};
template<std::size_t I, typename T>
void assert_sfinae_arg_at() {
CT_ASSERT(is_substitution_failure_arg_at<I, T>::value);
}
int main() {
assert_sfinae_arg_at<0, int>();
assert_sfinae_arg_at<0, int &>();
assert_sfinae_arg_at<0, int (* const &)()>();
assert_sfinae_arg_at<0, int (foo::* &)()>();
assert_sfinae_arg_at<0, int (foo::* const)()>();
assert_sfinae_arg_at<0, int (foo::* const &)()>();
assert_sfinae_arg_at<0, int (foo::* volatile)()>();
auto lambda = [](){};
assert_sfinae_arg_at<0, decltype(lambda)>();
assert_sfinae_arg_at<0, decltype(lambda)&>();
assert_sfinae_arg_at<0, void>();
using f = int(int, int);
assert_sfinae_arg_at<2, f>();
assert_sfinae_arg_at<17, f>();
using g = int(foo::*)(int, int);
assert_sfinae_arg_at<3, g>();
assert_sfinae_arg_at<4, g>();
}