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- /*!
- @file
- Forward declares `boost::hana::div`.
- @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)
- */
- #ifndef BOOST_HANA_FWD_DIV_HPP
- #define BOOST_HANA_FWD_DIV_HPP
- #include <boost/hana/config.hpp>
- #include <boost/hana/core/when.hpp>
- BOOST_HANA_NAMESPACE_BEGIN
- //! Generalized integer division.
- //! @ingroup group-EuclideanRing
- //!
- //!
- //! Cross-type version of the method
- //! --------------------------------
- //! The `div` method is "overloaded" to handle distinct data types
- //! with certain properties. Specifically, `div` 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, the `div` method is defined as
- //! @code
- //! div(x, y) = div(to<C>(x), to<C>(y))
- //! @endcode
- //!
- //!
- //! Example
- //! -------
- //! @include example/div.cpp
- #ifdef BOOST_HANA_DOXYGEN_INVOKED
- constexpr auto div = [](auto&& x, auto&& y) -> decltype(auto) {
- return tag-dispatched;
- };
- #else
- template <typename T, typename U, typename = void>
- struct div_impl : div_impl<T, U, when<true>> { };
- struct div_t {
- template <typename X, typename Y>
- constexpr decltype(auto) operator()(X&& x, Y&& y) const;
- };
- constexpr div_t div{};
- #endif
- BOOST_HANA_NAMESPACE_END
- #endif // !BOOST_HANA_FWD_DIV_HPP
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