hana/example/sequence/foldable.cpp
2017-01-07 14:14:18 -08:00

28 lines
669 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/fold_left.hpp>
#include <boost/hana/tuple.hpp>
#include <sstream>
namespace hana = boost::hana;
auto to_string = [](auto x) {
std::ostringstream ss;
ss << x;
return ss.str();
};
auto show = [](auto x, auto y) {
return "(" + to_string(x) + " + " + to_string(y) + ")";
};
int main() {
BOOST_HANA_RUNTIME_CHECK(
hana::fold_left(hana::make_tuple(2, "3", '4'), "1", show) == "(((1 + 2) + 3) + 4)"
);
}