Edit: /usr/include/boost/hana/is_empty.hpp (1244B)
/*!
@file
Defines `boost::hana::is_empty`.
@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_IS_EMPTY_HPP
#define BOOST_HANA_IS_EMPTY_HPP
#include
#include
#include
#include
BOOST_HANA_NAMESPACE_BEGIN
//! @cond
template
constexpr auto is_empty_t::operator()(Xs const& xs) const {
using It = typename hana::tag_of::type;
using IsEmpty = BOOST_HANA_DISPATCH_IF(is_empty_impl,
hana::Iterable::value
);
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::Iterable::value,
"hana::is_empty(xs) requires 'xs' to be an Iterable");
#endif
return IsEmpty::apply(xs);
}
//! @endcond
template
struct is_empty_impl> : default_ {
template
static constexpr auto apply(Args&& ...) = delete;
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_IS_EMPTY_HPP