mirror of
https://github.com/boostorg/hana.git
synced 2026-02-01 08:32:11 +00:00
152 lines
3.4 KiB
C++
152 lines
3.4 KiB
C++
/*
|
|
@copyright Louis Dionne 2015
|
|
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/bool.hpp>
|
|
#include <boost/hana/config.hpp>
|
|
#include <boost/hana/ext/std/integral_constant.hpp>
|
|
#include <boost/hana/functional.hpp>
|
|
#include <boost/hana/integral_constant.hpp>
|
|
#include <boost/hana/tuple.hpp>
|
|
#include <boost/hana/type.hpp>
|
|
|
|
#include <type_traits>
|
|
#include <vector>
|
|
using namespace boost::hana;
|
|
|
|
|
|
int main() {
|
|
|
|
{
|
|
|
|
//! [and_]
|
|
BOOST_HANA_CONSTANT_CHECK(and_(true_, true_, true_, true_));
|
|
BOOST_HANA_CONSTEXPR_CHECK(!and_(true_, false, true_, true_));
|
|
//! [and_]
|
|
|
|
}{
|
|
|
|
//! [or_]
|
|
BOOST_HANA_CONSTANT_CHECK(or_(false_, false_, true_));
|
|
BOOST_HANA_CONSTANT_CHECK(!or_(false_, false_, false_));
|
|
//! [or_]
|
|
|
|
}{
|
|
|
|
//! [if_]
|
|
BOOST_HANA_CONSTEXPR_CHECK(if_(true, 1, 2) == 1);
|
|
BOOST_HANA_CONSTEXPR_CHECK(if_(false, 1, 2) == 2);
|
|
|
|
BOOST_HANA_CONSTEXPR_CHECK(
|
|
if_(true_,
|
|
make<Tuple>('t', 'r', 'u', 'e'),
|
|
make<Tuple>('f', 'a', 'l', 's', 'e')
|
|
)
|
|
==
|
|
make<Tuple>('t', 'r', 'u', 'e')
|
|
);
|
|
//! [if_]
|
|
|
|
}{
|
|
|
|
//! [not_]
|
|
BOOST_HANA_CONSTANT_CHECK(not_(true_) == false_);
|
|
BOOST_HANA_CONSTEXPR_CHECK(not_(false) == true);
|
|
//! [not_]
|
|
|
|
}{
|
|
|
|
//! [heterogeneous_eval_if]
|
|
BOOST_HANA_CONSTEXPR_LAMBDA auto safe_make_unsigned = [](auto t) {
|
|
return eval_if(trait<std::is_integral>(t),
|
|
[=](auto id) { return id(template_<std::make_unsigned_t>)(t); },
|
|
always(t)
|
|
);
|
|
};
|
|
|
|
BOOST_HANA_CONSTANT_CHECK(safe_make_unsigned(type<void>) == type<void>);
|
|
BOOST_HANA_CONSTANT_CHECK(safe_make_unsigned(type<int>) == type<unsigned int>);
|
|
//! [heterogeneous_eval_if]
|
|
(void)safe_make_unsigned;
|
|
|
|
//! [homogeneous_eval_if]
|
|
BOOST_HANA_CONSTEXPR_LAMBDA auto safe_divide = [](auto x, auto y) {
|
|
return eval_if(y == 0,
|
|
[=](auto) { return 0; },
|
|
[=](auto id) { return id(x) / y; }
|
|
);
|
|
};
|
|
|
|
BOOST_HANA_CONSTEXPR_CHECK(safe_divide(6, 3) == 2);
|
|
BOOST_HANA_CONSTEXPR_CHECK(safe_divide(6, 0) == 0);
|
|
//! [homogeneous_eval_if]
|
|
|
|
}{
|
|
|
|
//! [homogeneous_while]
|
|
std::vector<int> ints;
|
|
int final_state = while_(_ < 10, 0, [&](int i) {
|
|
ints.push_back(i);
|
|
return i + 1;
|
|
});
|
|
|
|
// The state is known only at runtime
|
|
BOOST_HANA_RUNTIME_CHECK(final_state == 10);
|
|
|
|
BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
|
|
//! [homogeneous_while]
|
|
|
|
}{
|
|
|
|
//! [heterogeneous_while]
|
|
using namespace literals;
|
|
std::vector<int> ints;
|
|
auto final_state = while_(_ < 10_c, 0_c, [&](auto i) {
|
|
ints.push_back(i);
|
|
return i + 1_c;
|
|
});
|
|
|
|
// The state is known at compile-time
|
|
BOOST_HANA_CONSTANT_CHECK(final_state == 10_c);
|
|
|
|
BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
|
|
//! [heterogeneous_while]
|
|
|
|
}{
|
|
|
|
//! [homogeneous_until]
|
|
std::vector<int> ints;
|
|
int final_state = until(_ == 10, 0, [&](int i) {
|
|
ints.push_back(i);
|
|
return i + 1;
|
|
});
|
|
|
|
// The state is known only at runtime
|
|
BOOST_HANA_RUNTIME_CHECK(final_state == 10);
|
|
|
|
BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
|
|
//! [homogeneous_until]
|
|
|
|
}{
|
|
|
|
//! [heterogeneous_until]
|
|
using namespace literals;
|
|
std::vector<int> ints;
|
|
auto final_state = until(_ == 10_c, 0_c, [&](auto i) {
|
|
ints.push_back(i);
|
|
return i + 1_c;
|
|
});
|
|
|
|
// The state is known at compile-time
|
|
BOOST_HANA_CONSTANT_CHECK(final_state == 10_c);
|
|
|
|
BOOST_HANA_RUNTIME_CHECK(ints == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
|
|
//! [heterogeneous_until]
|
|
|
|
}
|
|
|
|
}
|