1/*!
2@file
3Defines `boost::hana::remove`.
4
5Copyright Louis Dionne 2013-2022
6Distributed under the Boost Software License, Version 1.0.
7(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
8 */
9
10#ifndef BOOST_HANA_REMOVE_HPP
11#define BOOST_HANA_REMOVE_HPP
12
13#include <boost/hana/fwd/remove.hpp>
14
15#include <boost/hana/concept/monad_plus.hpp>
16#include <boost/hana/config.hpp>
17#include <boost/hana/core/dispatch.hpp>
18#include <boost/hana/equal.hpp>
19#include <boost/hana/filter.hpp>
20#include <boost/hana/functional/compose.hpp>
21#include <boost/hana/not.hpp>
22
23
24namespace boost { namespace hana {
25 //! @cond
26 template <typename Xs, typename Value>
27 constexpr auto remove_t::operator()(Xs&& xs, Value&& value) const {
28 using M = typename hana::tag_of<Xs>::type;
29 using Remove = BOOST_HANA_DISPATCH_IF(remove_impl<M>,
30 hana::MonadPlus<M>::value
31 );
32
33 #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
34 static_assert(hana::MonadPlus<M>::value,
35 "hana::remove(xs, value) requires 'xs' to be a MonadPlus");
36 #endif
37
38 return Remove::apply(static_cast<Xs&&>(xs),
39 static_cast<Value&&>(value));
40 }
41 //! @endcond
42
43 template <typename M, bool condition>
44 struct remove_impl<M, when<condition>> : default_ {
45 template <typename Xs, typename Value>
46 static constexpr auto apply(Xs&& xs, Value&& value) {
47 return hana::filter(static_cast<Xs&&>(xs),
48 hana::compose(hana::not_,
49 hana::equal.to(static_cast<Value&&>(value))));
50 }
51 };
52}} // end namespace boost::hana
53
54#endif // !BOOST_HANA_REMOVE_HPP
55

source code of boost/libs/hana/include/boost/hana/remove.hpp