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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/at_key.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/map.hpp>
#include <boost/hana/pair.hpp>
#include <utility>
namespace hana = boost::hana;
template <typename T>
T const& cref(T& t) { return t; }
int main() {
// using at_key
{
auto xs = hana::make_map(
hana::make_pair(hana::int_c<0>, 0),
hana::make_pair(hana::int_c<1>, '1'),
hana::make_pair(hana::int_c<2>, 2.2)
);
// Make sure we return lvalue-references
BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<0>) == 0);
BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<1>) == '1');
BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<2>) == 2.2);
int& a = hana::at_key(xs, hana::int_c<0>);
char& b = hana::at_key(xs, hana::int_c<1>);
double& c = hana::at_key(xs, hana::int_c<2>);
a = 9;
b = '9';
c = 9.9;
// Make sure we return lvalue-references to const on a const map
int const& ca = hana::at_key(cref(xs), hana::int_c<0>);
char const& cb = hana::at_key(cref(xs), hana::int_c<1>);
double const& cc = hana::at_key(cref(xs), hana::int_c<2>);
BOOST_HANA_RUNTIME_CHECK(ca == 9);
BOOST_HANA_RUNTIME_CHECK(cb == '9');
BOOST_HANA_RUNTIME_CHECK(cc == 9.9);
}
// using operator[]
{
auto xs = hana::make_map(
hana::make_pair(hana::int_c<0>, 0),
hana::make_pair(hana::int_c<1>, '1'),
hana::make_pair(hana::int_c<2>, 2.2)
);
BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<0>] == 0);
BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<1>] == '1');
BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<2>] == 2.2);
xs[hana::int_c<0>] = 9;
xs[hana::int_c<1>] = '9';
xs[hana::int_c<2>] = 9.9;
BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<0>] == 9);
BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<1>] == '9');
BOOST_HANA_RUNTIME_CHECK(xs[hana::int_c<2>] == 9.9);
}
// Make sure we return a rvalue-reference from a temporary map
// (https://github.com/boostorg/hana/issues/90)
{
auto xs = hana::make_map(
hana::make_pair(hana::int_c<0>, 0),
hana::make_pair(hana::int_c<1>, '1'),
hana::make_pair(hana::int_c<2>, 2.2)
);
char&& c = hana::at_key(std::move(xs), hana::int_c<1>);
BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<1>) == '1');
c = '9';
BOOST_HANA_RUNTIME_CHECK(hana::at_key(xs, hana::int_c<1>) == '9');
}
}
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