std::ratio< Num, Denom > Class Template Reference

Description

template<std::intmax_t Num, std::intmax_t Denom>
class std::ratio< Num, Denom >

Adaptation of std::ratio for Hana.

Modeled concepts

1. Comparable
std::ratios are compared for equality using std::ratio_equal.

   // 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/equal.hpp>
   #include <boost/hana/ext/std/ratio.hpp>
   #include <boost/hana/not_equal.hpp>
   
   #include <ratio>
   namespace hana = boost::hana;
   
   
   BOOST_HANA_CONSTANT_CHECK(hana::equal(std::ratio<3, 4>{}, std::ratio<15, 20>{}));
   BOOST_HANA_CONSTANT_CHECK(hana::not_equal(std::ratio<3, 4>{}, std::ratio<3, 5>{}));
   
   int main() { }

2. Orderable
std::ratios are ordered using std::ratio_less.

   // 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/ext/std/ratio.hpp>
   #include <boost/hana/less.hpp>
   #include <boost/hana/less_equal.hpp>
   
   #include <ratio>
   namespace hana = boost::hana;
   
   
   BOOST_HANA_CONSTANT_CHECK(hana::less(std::ratio<3, 12>{}, std::ratio<5, 12>{}));
   BOOST_HANA_CONSTANT_CHECK(hana::less_equal(std::ratio<6, 12>{}, std::ratio<4, 8>{}));
   
   int main() { }

3. Monoid, Group, Ring, and EuclideanRing
std::ratios are added, subtracted, multiplied and divided using std::ratio_add, std::ratio_subtract, std::ratio_multiply and std::ratio_divide, respectively. Furthermore, the neutral element for the additive operation is std::ratio<0, 1>{}, and the neutral element for the multiplicative operation is std::ratio<1, 1>{}.

   // 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/div.hpp>
   #include <boost/hana/equal.hpp>
   #include <boost/hana/ext/std/ratio.hpp>
   #include <boost/hana/minus.hpp>
   #include <boost/hana/mod.hpp>
   #include <boost/hana/mult.hpp>
   #include <boost/hana/one.hpp>
   #include <boost/hana/plus.hpp>
   #include <boost/hana/zero.hpp>
   
   #include <ratio>
   namespace hana = boost::hana;
   
   
   BOOST_HANA_CONSTANT_CHECK(hana::equal(
       hana::plus(std::ratio<5, 3>{}, std::ratio<3, 12>{}),
       std::ratio<23, 12>{}
   ));
   
   BOOST_HANA_CONSTANT_CHECK(hana::equal(
       hana::minus(std::ratio<5, 3>{}, std::ratio<3, 13>{}),
       std::ratio<56, 39>{}
   ));
   
   BOOST_HANA_CONSTANT_CHECK(hana::equal(
       hana::mult(std::ratio<5, 3>{}, std::ratio<3, 13>{}),
       std::ratio<15, 39>{}
   ));
   
   BOOST_HANA_CONSTANT_CHECK(hana::equal(
       hana::div(std::ratio<5, 3>{}, std::ratio<3, 13>{}),
       std::ratio<65, 9>{}
   ));
   
   // The mod of two ratios is always 0, because they can always be
   // divided without remainder.
   BOOST_HANA_CONSTANT_CHECK(hana::equal(
       hana::mod(std::ratio<5, 3>{}, std::ratio<3, 13>{}),
       std::ratio<0>{}
   ));
   
   BOOST_HANA_CONSTANT_CHECK(hana::equal(
       hana::zero<hana::ext::std::ratio_tag>(),
       std::ratio<0>{}
   ));
   
   BOOST_HANA_CONSTANT_CHECK(hana::equal(
       hana::one<hana::ext::std::ratio_tag>(),
       std::ratio<1>{}
   ));
   
   int main() { }