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152 lines
3.4 KiB
C++
152 lines
3.4 KiB
C++
/*
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@copyright Louis Dionne 2014
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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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*/
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#include <boost/hana/assert.hpp>
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#include <boost/hana/bool.hpp>
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#include <boost/hana/config.hpp>
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#include <boost/hana/ext/std/integral_constant.hpp>
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#include <boost/hana/functional.hpp>
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#include <boost/hana/integral_constant.hpp>
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#include <boost/hana/tuple.hpp>
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#include <boost/hana/type.hpp>
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#include <type_traits>
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#include <vector>
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using namespace boost::hana;
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int main() {
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{
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//! [and_]
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BOOST_HANA_CONSTANT_CHECK(and_(true_, true_, true_, true_));
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BOOST_HANA_CONSTEXPR_CHECK(!and_(true_, false, true_, true_));
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//! [and_]
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}{
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//! [or_]
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BOOST_HANA_CONSTANT_CHECK(or_(false_, false_, true_));
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BOOST_HANA_CONSTANT_CHECK(!or_(false_, false_, false_));
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//! [or_]
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}{
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//! [if_]
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BOOST_HANA_CONSTEXPR_CHECK(if_(true, 1, 2) == 1);
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BOOST_HANA_CONSTEXPR_CHECK(if_(false, 1, 2) == 2);
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BOOST_HANA_CONSTEXPR_CHECK(
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if_(true_,
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make<Tuple>('t', 'r', 'u', 'e'),
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make<Tuple>('f', 'a', 'l', 's', 'e')
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)
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==
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make<Tuple>('t', 'r', 'u', 'e')
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);
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//! [if_]
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}{
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//! [not_]
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BOOST_HANA_CONSTANT_CHECK(not_(true_) == false_);
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BOOST_HANA_CONSTEXPR_CHECK(not_(false) == true);
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//! [not_]
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}{
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//! [heterogeneous_eval_if]
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BOOST_HANA_CONSTEXPR_LAMBDA auto safe_make_unsigned = [](auto t) {
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return eval_if(trait<std::is_integral>(t),
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[=](auto id) { return id(template_<std::make_unsigned_t>)(t); },
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always(t)
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);
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};
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BOOST_HANA_CONSTANT_CHECK(safe_make_unsigned(type<void>) == type<void>);
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BOOST_HANA_CONSTANT_CHECK(safe_make_unsigned(type<int>) == type<unsigned int>);
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//! [heterogeneous_eval_if]
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(void)safe_make_unsigned;
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//! [homogeneous_eval_if]
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BOOST_HANA_CONSTEXPR_LAMBDA auto safe_divide = [](auto x, auto y) {
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return eval_if(y == 0,
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[=](auto) { return 0; },
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[=](auto id) { return id(x) / y; }
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);
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};
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BOOST_HANA_CONSTEXPR_CHECK(safe_divide(6, 3) == 2);
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BOOST_HANA_CONSTEXPR_CHECK(safe_divide(6, 0) == 0);
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//! [homogeneous_eval_if]
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}{
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//! [homogeneous_while]
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std::vector<int> ints;
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int final_state = while_(_ < 10, 0, [&](int i) {
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ints.push_back(i);
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return i + 1;
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});
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// The state is known only at runtime
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BOOST_HANA_RUNTIME_CHECK(final_state == 10);
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BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
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//! [homogeneous_while]
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}{
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//! [heterogeneous_while]
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using namespace literals;
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std::vector<int> ints;
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auto final_state = while_(_ < 10_c, 0_c, [&](auto i) {
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ints.push_back(i);
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return i + 1_c;
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});
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// The state is known at compile-time
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BOOST_HANA_CONSTANT_CHECK(final_state == 10_c);
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BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
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//! [heterogeneous_while]
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}{
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//! [homogeneous_until]
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std::vector<int> ints;
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int final_state = until(_ == 10, 0, [&](int i) {
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ints.push_back(i);
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return i + 1;
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});
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// The state is known only at runtime
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BOOST_HANA_RUNTIME_CHECK(final_state == 10);
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BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
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//! [homogeneous_until]
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}{
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//! [heterogeneous_until]
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using namespace literals;
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std::vector<int> ints;
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auto final_state = until(_ == 10_c, 0_c, [&](auto i) {
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ints.push_back(i);
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return i + 1_c;
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});
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// The state is known at compile-time
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BOOST_HANA_CONSTANT_CHECK(final_state == 10_c);
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BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
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//! [heterogeneous_until]
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}
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}
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