boost/libs/hana/example/struct/foldable.cpp
2018-01-12 21:47:58 +01:00

30 lines
844 B
C++

// 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/define_struct.hpp>
#include <boost/hana/fold_left.hpp>
#include <boost/hana/second.hpp>
namespace hana = boost::hana;
struct Classroom {
BOOST_HANA_DEFINE_STRUCT(Classroom,
(unsigned short, boys),
(unsigned short, girls)
);
};
int main() {
constexpr Classroom compsci{20, 3};
BOOST_HANA_CONSTEXPR_CHECK(
hana::fold_left(compsci, 0, [](auto total, auto member) {
// first(member) is the name of the member, here
// "boys" or "girls", and second(member) is its value.
return hana::second(member) + total;
}) == 23
);
}