/*!
@file
Defines `boost::hana::any_of`.
@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_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) {
return prev_cond ? hana::true_c
: any_of_impl::any_of_helper<k + 1, Len>::apply(
hana::if_(pred(hana::at_c<k>(xs)), hana::true_c, hana::false_c),
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) {
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_<done>{},
hana::if_(pred(hana::front(xs)), hana::true_{}, hana::false_{}),
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) {
constexpr bool done = decltype(hana::is_empty(hana::drop_front(xs)))::value;
return lazy_any_of_helper(hana::bool_c<done>,
hana::if_(pred(hana::front(xs)), hana::true_c, hana::false_c),
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