ecency-mobile/ios/Pods/boost-for-react-native/boost/hana/fwd/mod.hpp

63 lines
2.0 KiB
C++

/*!
@file
Forward declares `boost::hana::mod`.
@copyright Louis Dionne 2013-2016
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_HANA_FWD_MOD_HPP
#define BOOST_HANA_FWD_MOD_HPP
#include <boost/hana/config.hpp>
#include <boost/hana/core/when.hpp>
BOOST_HANA_NAMESPACE_BEGIN
//! Generalized integer modulus.
//! @ingroup group-EuclideanRing
//!
//! Given two elements of an EuclideanRing `x` and `y`, with `y`
//! nonzero, `mod` returns the modulus of the division of `x` by `y`.
//! In other words, `mod` can be seen as an equivalent to `%`.
//!
//! Cross-type version of the method
//! --------------------------------
//! The `mod` method is "overloaded" to handle distinct data types
//! with certain properties. Specifically, `mod` is defined for
//! _distinct_ data types `A` and `B` such that
//! 1. `A` and `B` share a common data type `C`, as determined by the
//! `common` metafunction
//! 2. `A`, `B` and `C` are all `EuclideanRing`s when taken individually
//! 3. `to<C> : A -> B` and `to<C> : B -> C` are `Ring`-embeddings, as
//! determined by the `is_embedding` metafunction.
//!
//! In that case, `mod` is defined as
//! @code
//! mod(x, y) = mod(to<C>(x), to<C>(y))
//! @endcode
//!
//!
//! Example
//! -------
//! @include example/mod.cpp
#ifdef BOOST_HANA_DOXYGEN_INVOKED
constexpr auto mod = [](auto&& x, auto&& y) -> decltype(auto) {
return tag-dispatched;
};
#else
template <typename T, typename U, typename = void>
struct mod_impl : mod_impl<T, U, when<true>> { };
struct mod_t {
template <typename X, typename Y>
constexpr decltype(auto) operator()(X&& x, Y&& y) const;
};
constexpr mod_t mod{};
#endif
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_FWD_MOD_HPP