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Diffstat (limited to 'boost/hana/remove_if.hpp')
-rw-r--r-- | boost/hana/remove_if.hpp | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/boost/hana/remove_if.hpp b/boost/hana/remove_if.hpp new file mode 100644 index 0000000000..fb85c3d424 --- /dev/null +++ b/boost/hana/remove_if.hpp @@ -0,0 +1,52 @@ +/*! +@file +Defines `boost::hana::remove_if`. + +@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_REMOVE_IF_HPP +#define BOOST_HANA_REMOVE_IF_HPP + +#include <boost/hana/fwd/remove_if.hpp> + +#include <boost/hana/concept/monad_plus.hpp> +#include <boost/hana/config.hpp> +#include <boost/hana/core/dispatch.hpp> +#include <boost/hana/filter.hpp> +#include <boost/hana/functional/compose.hpp> +#include <boost/hana/not.hpp> + + +BOOST_HANA_NAMESPACE_BEGIN + //! @cond + template <typename Xs, typename Pred> + constexpr auto remove_if_t::operator()(Xs&& xs, Pred&& pred) const { + using M = typename hana::tag_of<Xs>::type; + using RemoveIf = BOOST_HANA_DISPATCH_IF(remove_if_impl<M>, + hana::MonadPlus<M>::value + ); + + #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS + static_assert(hana::MonadPlus<M>::value, + "hana::remove_if(xs, predicate) requires 'xs' to be a MonadPlus"); + #endif + + return RemoveIf::apply(static_cast<Xs&&>(xs), + static_cast<Pred&&>(pred)); + } + //! @endcond + + template <typename M, bool condition> + struct remove_if_impl<M, when<condition>> : default_ { + template <typename Xs, typename Pred> + static constexpr auto apply(Xs&& xs, Pred&& pred) { + return hana::filter(static_cast<Xs&&>(xs), + hana::compose(hana::not_, static_cast<Pred&&>(pred))); + } + }; +BOOST_HANA_NAMESPACE_END + +#endif // !BOOST_HANA_REMOVE_IF_HPP |