Edit: /usr/include/boost/hana/extract.hpp (1248B)
/*!
@file
Defines `boost::hana::extract`.
@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_EXTRACT_HPP
#define BOOST_HANA_EXTRACT_HPP
#include
#include
#include
#include
BOOST_HANA_NAMESPACE_BEGIN
//! @cond
template
constexpr decltype(auto) extract_t::operator()(W_&& w) const {
using W = typename hana::tag_of::type;
using Extract = BOOST_HANA_DISPATCH_IF(extract_impl,
hana::Comonad::value
);
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::Comonad::value,
"hana::extract(w) requires 'w' to be a Comonad");
#endif
return Extract::apply(static_cast(w));
}
//! @endcond
template
struct extract_impl> : default_ {
template
static constexpr auto apply(Args&& ...args) = delete;
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_EXTRACT_HPP