39 lines
944 B
C++
39 lines
944 B
C++
// Copyright Louis Dionne 2013-2017
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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#include <boost/hana/assert.hpp>
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#include <boost/hana/fold_left.hpp>
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#include <boost/hana/tuple.hpp>
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#include <sstream>
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#include <string>
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namespace hana = boost::hana;
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auto to_string = [](auto x) {
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std::ostringstream ss;
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ss << x;
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return ss.str();
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};
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int main() {
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auto f = [=](std::string s, auto element) {
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return "f(" + s + ", " + to_string(element) + ")";
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};
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// with an initial state
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BOOST_HANA_RUNTIME_CHECK(
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hana::fold_left(hana::make_tuple(2, '3', 4, 5.0), "1", f)
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==
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"f(f(f(f(1, 2), 3), 4), 5)"
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);
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// without initial state
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BOOST_HANA_RUNTIME_CHECK(
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hana::fold_left(hana::make_tuple("1", 2, '3', 4, 5.0), f)
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==
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"f(f(f(f(1, 2), 3), 4), 5)"
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);
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}
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