Edit: /usr/include/boost/hana/prefix.hpp (1597B)
/*!
@file
Defines `boost::hana::prefix`.
@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_PREFIX_HPP
#define BOOST_HANA_PREFIX_HPP
#include
#include
#include
#include
#include
#include
#include
#include
BOOST_HANA_NAMESPACE_BEGIN
//! @cond
template
constexpr auto prefix_t::operator()(Xs&& xs, Pref&& pref) const {
using M = typename hana::tag_of::type;
using Prefix = BOOST_HANA_DISPATCH_IF(prefix_impl,
hana::MonadPlus::value
);
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::MonadPlus::value,
"hana::prefix(xs, pref) requires 'xs' to be a MonadPlus");
#endif
return Prefix::apply(static_cast(xs), static_cast(pref));
}
//! @endcond
template
struct prefix_impl> : default_ {
template
static constexpr decltype(auto) apply(Xs&& xs, Z&& z) {
return hana::chain(static_cast(xs),
hana::partial(hana::append, hana::lift(static_cast(z))));
}
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_PREFIX_HPP