101 lines
2.7 KiB
C++
101 lines
2.7 KiB
C++
/*=============================================================================
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Copyright (c) 2017 Paul Fultz II
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fix.cpp
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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==============================================================================*/
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#include <boost/hof/fix.hpp>
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#include <boost/hof/static.hpp>
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#include <boost/hof/reveal.hpp>
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#include <boost/hof/result.hpp>
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#include "test.hpp"
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#include <memory>
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struct factorial_t
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{
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template<class Self, class T>
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T operator()(Self s, T x) const noexcept
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{
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return x == 0 ? 1 : x * s(x-1);
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}
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};
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struct factorial_constexpr_t
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{
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template<class Self, class T>
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constexpr T operator()(Self s, T x) const noexcept
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{
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return x == 0 ? 1 : x * s(x-1);
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}
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};
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struct factorial_move_t
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{
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std::unique_ptr<int> i;
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factorial_move_t() : i(new int(1))
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{}
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template<class Self, class T>
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T operator()(const Self& s, T x) const
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{
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return x == 0 ? *i : x * s(x-1);
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}
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};
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static constexpr boost::hof::fix_adaptor<factorial_t> factorial = {};
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static constexpr boost::hof::fix_adaptor<factorial_constexpr_t> factorial_constexpr = {};
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static constexpr boost::hof::static_<boost::hof::fix_adaptor<factorial_move_t> > factorial_move = {};
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#if BOOST_HOF_HAS_NOEXCEPT_DEDUCTION
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BOOST_HOF_TEST_CASE()
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{
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static_assert(noexcept(factorial(5)), "noexcept fix");
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}
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#endif
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BOOST_HOF_TEST_CASE()
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{
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const int r = factorial(5);
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BOOST_HOF_TEST_CHECK(r == 5*4*3*2*1);
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}
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BOOST_HOF_TEST_CASE()
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{
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const int r = boost::hof::reveal(factorial)(5);
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BOOST_HOF_TEST_CHECK(r == 5*4*3*2*1);
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}
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#if !BOOST_HOF_NO_EXPRESSION_SFINAE
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BOOST_HOF_TEST_CASE()
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{
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const int r = boost::hof::fix(boost::hof::result<int>(factorial_constexpr_t()))(5);
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BOOST_HOF_TEST_CHECK(r == 5*4*3*2*1);
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}
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BOOST_HOF_TEST_CASE()
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{
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const int r = boost::hof::result<int>(factorial_constexpr)(5);
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BOOST_HOF_TEST_CHECK(r == 5*4*3*2*1);
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}
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BOOST_HOF_TEST_CASE()
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{
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BOOST_HOF_STATIC_TEST_CHECK(boost::hof::fix(boost::hof::result<int>(factorial_constexpr_t()))(5) == 5*4*3*2*1);
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BOOST_HOF_STATIC_TEST_CHECK(boost::hof::result<int>(factorial_constexpr)(5) == 5*4*3*2*1);
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}
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#endif
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BOOST_HOF_TEST_CASE()
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{
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#if BOOST_HOF_HAS_GENERIC_LAMBDA
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auto factorial_ = boost::hof::fix([](auto s, auto x) -> decltype(x) { return x == 0 ? 1 : x * s(x-1); });
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int r = boost::hof::result<int>(factorial_)(5);
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BOOST_HOF_TEST_CHECK(r == 5*4*3*2*1);
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#endif
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}
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BOOST_HOF_TEST_CASE()
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{
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const int r = factorial_move(5);
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BOOST_HOF_TEST_CHECK(r == 5*4*3*2*1);
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BOOST_HOF_TEST_CHECK(boost::hof::fix(factorial_move_t())(5) == 5*4*3*2*1);
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}
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