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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/equal.hpp>
#include <boost/hana/scan_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 f = [](auto state, auto element) {
return "f(" + to_string(state) + ", " + to_string(element) + ")";
};
int main() {
// with initial state
BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(2, "3", '4'), 1, f) == hana::make_tuple(
1,
"f(1, 2)",
"f(f(1, 2), 3)",
"f(f(f(1, 2), 3), 4)"
));
// without initial state
BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(1, "2", '3'), f) == hana::make_tuple(
1,
"f(1, 2)",
"f(f(1, 2), 3)"
));
}
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