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// Copyright Louis Dionne 2013-2017
// 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/hana/assert.hpp>
#include <boost/hana/not.hpp>
#include <boost/hana/type.hpp>
#include <string>
#include <vector>
namespace hana = boost::hana;
int main() {
// Checking for a member
struct Person { std::string name; };
auto has_name = hana::is_valid([](auto&& p) -> decltype((void)p.name) { });
Person joe{"Joe"};
static_assert(has_name(joe), "");
static_assert(!has_name(1), "");
// Checking for a nested type
auto has_value_type = hana::is_valid([](auto t) -> hana::type<
typename decltype(t)::type::value_type
> { });
static_assert(has_value_type(hana::type_c<std::vector<int>>), "");
static_assert(!has_value_type(hana::type_c<Person>), "");
}
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