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// Copyright 2022 Dmitry Arkhipov (grisumbras@gmail.com)
//
// Distributed under the Boost Software License, Version 1.0.
//
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
#include <boost/mp11/utility.hpp>
#include <boost/core/lightweight_test_trait.hpp>
#include <cstddef>
template<class T>
using has_size_t_difference_type
= std::is_same<typename T::difference_type, std::size_t>;
struct X
{
};
struct Y
{
using difference_type = int;
};
struct Z
{
using difference_type = std::size_t;
};
int main()
{
using boost::mp11::mp_valid_and_true;
using boost::mp11::mp_valid_and_true_q;
using boost::mp11::mp_quote;
BOOST_TEST_TRAIT_FALSE((mp_valid_and_true<has_size_t_difference_type, X>));
BOOST_TEST_TRAIT_FALSE((mp_valid_and_true<has_size_t_difference_type, Y>));
BOOST_TEST_TRAIT_TRUE((mp_valid_and_true<has_size_t_difference_type, Z>));
using Q_size_t_diff = mp_quote<has_size_t_difference_type>;
BOOST_TEST_TRAIT_FALSE((mp_valid_and_true_q<Q_size_t_diff, X>));
BOOST_TEST_TRAIT_FALSE((mp_valid_and_true_q<Q_size_t_diff, Y>));
BOOST_TEST_TRAIT_TRUE((mp_valid_and_true_q<Q_size_t_diff, Z>));
return boost::report_errors();
}
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