/*! @file Defines `boost::hana::any_of`. @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_ANY_OF_HPP #define BOOST_HANA_ANY_OF_HPP #include <boost/hana/fwd/any_of.hpp> #include <boost/hana/accessors.hpp> #include <boost/hana/at.hpp> #include <boost/hana/bool.hpp> #include <boost/hana/concept/searchable.hpp> #include <boost/hana/concept/sequence.hpp> #include <boost/hana/concept/struct.hpp> #include <boost/hana/config.hpp> #include <boost/hana/core/dispatch.hpp> #include <boost/hana/drop_front.hpp> #include <boost/hana/first.hpp> #include <boost/hana/front.hpp> #include <boost/hana/functional/compose.hpp> #include <boost/hana/if.hpp> #include <boost/hana/is_empty.hpp> #include <boost/hana/length.hpp> #include <cstddef> BOOST_HANA_NAMESPACE_BEGIN //! @cond template <typename Xs, typename Pred> constexpr auto any_of_t::operator()(Xs&& xs, Pred&& pred) const { using S = typename hana::tag_of<Xs>::type; using AnyOf = BOOST_HANA_DISPATCH_IF(any_of_impl<S>, hana::Searchable<S>::value ); #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS static_assert(hana::Searchable<S>::value, "hana::any_of(xs, pred) requires 'xs' to be a Searchable"); #endif return AnyOf::apply(static_cast<Xs&&>(xs), static_cast<Pred&&>(pred)); } //! @endcond template <typename S, bool condition> struct any_of_impl<S, when<condition>> : default_ { template <typename ...Args> static constexpr auto apply(Args&& ...) = delete; }; template <typename S> struct any_of_impl<S, when<Sequence<S>::value>> { //! @cond template <std::size_t k, std::size_t Len> struct any_of_helper { template <typename Xs, typename Pred> static constexpr auto apply(bool prev_cond, Xs&& xs, Pred&& pred) { auto cond = hana::if_(pred(hana::at_c<k>(xs)), hana::true_c, hana::false_c); return prev_cond ? hana::true_c : any_of_impl::any_of_helper<k + 1, Len>::apply(cond, static_cast<Xs&&>(xs), static_cast<Pred&&>(pred)); } template <typename Xs, typename Pred> static constexpr auto apply(hana::true_, Xs&&, Pred&&) { return hana::true_c; } template <typename Xs, typename Pred> static constexpr auto apply(hana::false_, Xs&& xs, Pred&& pred) { auto cond = hana::if_(pred(hana::at_c<k>(xs)), hana::true_c, hana::false_c); return any_of_impl::any_of_helper<k + 1, Len>::apply(cond, static_cast<Xs&&>(xs), static_cast<Pred&&>(pred)); } }; template <std::size_t Len> struct any_of_helper<Len, Len> { template <typename Cond, typename Xs, typename Pred> static constexpr auto apply(Cond cond, Xs&&, Pred&&) { return cond; } }; template <typename Xs, typename Pred> static constexpr auto apply(Xs&& xs, Pred&& pred) { constexpr std::size_t len = decltype(hana::length(xs))::value; return any_of_impl::any_of_helper<0, len>::apply(hana::false_c, static_cast<Xs&&>(xs), static_cast<Pred&&>(pred)); } //! @endcond }; template <typename It> struct any_of_impl<It, when< hana::Iterable<It>::value && !Sequence<It>::value >> { template <typename Xs, typename Pred> static constexpr auto lazy_any_of_helper(hana::false_, bool prev_cond, Xs&& xs, Pred&& pred) { auto cond = hana::if_(pred(hana::front(xs)), hana::true_c, hana::false_c); decltype(auto) tail = hana::drop_front(static_cast<Xs&&>(xs)); constexpr bool done = decltype(hana::is_empty(tail))::value; return prev_cond ? hana::true_c : lazy_any_of_helper(hana::bool_c<done>, cond, static_cast<decltype(tail)&&>(tail), static_cast<Pred&&>(pred)); } template <typename Xs, typename Pred> static constexpr auto lazy_any_of_helper(hana::false_, hana::true_, Xs&&, Pred&&) { return hana::true_c; } template <typename Xs, typename Pred> static constexpr auto lazy_any_of_helper(hana::false_, hana::false_, Xs&& xs, Pred&& pred) { auto cond = hana::if_(pred(hana::front(xs)), hana::true_c, hana::false_c); constexpr bool done = decltype(hana::is_empty(hana::drop_front(xs)))::value; return lazy_any_of_helper(hana::bool_c<done>, cond, hana::drop_front(static_cast<Xs&&>(xs)), static_cast<Pred&&>(pred)); } template <typename Cond, typename Xs, typename Pred> static constexpr auto lazy_any_of_helper(hana::true_, Cond cond, Xs&&, Pred&&) { return cond; } template <typename Xs, typename Pred> static constexpr auto apply(Xs&& xs, Pred&& pred) { constexpr bool done = decltype(hana::is_empty(xs))::value; return lazy_any_of_helper(hana::bool_c<done>, hana::false_c, static_cast<Xs&&>(xs), static_cast<Pred&&>(pred)); } }; template <typename T, std::size_t N> struct any_of_impl<T[N]> { template <typename Xs, typename Pred> static constexpr bool any_of_helper(bool cond, Xs&& xs, Pred&& pred) { if (cond) return true; for (std::size_t i = 1; i < N; ++i) if (pred(static_cast<Xs&&>(xs)[i])) return true; return false; } // Since an array contains homogeneous data, if the predicate returns // a compile-time logical at any index, it must do so at every index // (because the type of the elements won't change)! In this case, we // then only need to evaluate the predicate on the first element. template <typename Xs, typename Pred> static constexpr auto any_of_helper(hana::true_, Xs&& /*xs*/, Pred&&) { return hana::true_c; } template <typename Xs, typename Pred> static constexpr auto any_of_helper(hana::false_, Xs&&, Pred&&) { return hana::false_c; } template <typename Xs, typename Pred> static constexpr auto apply(Xs&& xs, Pred&& pred) { auto cond = hana::if_(pred(static_cast<Xs&&>(xs)[0]), hana::true_c, hana::false_c); return any_of_helper(cond, static_cast<Xs&&>(xs), static_cast<Pred&&>(pred)); } }; template <typename S> struct any_of_impl<S, when<hana::Struct<S>::value>> { template <typename X, typename Pred> static constexpr decltype(auto) apply(X const&, Pred&& pred) { return hana::any_of(hana::accessors<S>(), hana::compose(static_cast<Pred&&>(pred), hana::first)); } }; BOOST_HANA_NAMESPACE_END #endif // !BOOST_HANA_ANY_OF_HPP