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

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1.7 KiB
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/*!
@file
Forward declares `boost::hana::symmetric_difference`.
@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_SYMMETRIC_DIFFERENCE_HPP
#define BOOST_HANA_FWD_SYMMETRIC_DIFFERENCE_HPP
#include <boost/hana/config.hpp>
#include <boost/hana/core/when.hpp>
BOOST_HANA_NAMESPACE_BEGIN
//! Returns the symmetric set-theoretic difference of two sets.
//! @relates hana::set
//!
//! Given two sets `xs` and `ys`, `symmetric_difference(xs, ys)` is a new
//! set containing all the elements of `xs` that are not contained in `ys`,
//! and all the elements of `ys` that are not contained in `xs`. The
//! symmetric difference of two sets satisfies the following:
//! @code
//! symmetric_difference(xs, ys) == union_(difference(xs, ys), difference(ys, xs))
//! @endcode
//!
//!
//! @param xs, ys
//! Two sets to compute the symmetric difference of.
//!
//!
//! Example
//! -------
//! @include example/symmetric_difference.cpp
#ifdef BOOST_HANA_DOXYGEN_INVOKED
constexpr auto symmetric_difference = [](auto&& xs, auto&& ys) {
return tag-dispatched;
};
#else
template <typename S, typename = void>
struct symmetric_difference_impl : symmetric_difference_impl<S, when<true>> { };
struct symmetric_difference_t {
template <typename Xs, typename Ys>
constexpr auto operator()(Xs&& xs, Ys&& ys) const;
};
constexpr symmetric_difference_t symmetric_difference{};
#endif
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_FWD_SYMMETRIC_DIFFERENCE_HPP