stabilize build system: depends, installer, boost/bdb fixes, cross targets groundwork
This commit is contained in:
@@ -0,0 +1,45 @@
|
||||
/*!
|
||||
@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 <boost/hana/fwd/is_empty.hpp>
|
||||
|
||||
#include <boost/hana/concept/iterable.hpp>
|
||||
#include <boost/hana/config.hpp>
|
||||
#include <boost/hana/core/dispatch.hpp>
|
||||
|
||||
|
||||
BOOST_HANA_NAMESPACE_BEGIN
|
||||
//! @cond
|
||||
template <typename Xs>
|
||||
constexpr auto is_empty_t::operator()(Xs const& xs) const {
|
||||
using It = typename hana::tag_of<Xs>::type;
|
||||
using IsEmpty = BOOST_HANA_DISPATCH_IF(is_empty_impl<It>,
|
||||
hana::Iterable<It>::value
|
||||
);
|
||||
|
||||
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
|
||||
static_assert(hana::Iterable<It>::value,
|
||||
"hana::is_empty(xs) requires 'xs' to be an Iterable");
|
||||
#endif
|
||||
|
||||
return IsEmpty::apply(xs);
|
||||
}
|
||||
//! @endcond
|
||||
|
||||
template <typename It, bool condition>
|
||||
struct is_empty_impl<It, when<condition>> : default_ {
|
||||
template <typename ...Args>
|
||||
static constexpr auto apply(Args&& ...) = delete;
|
||||
};
|
||||
BOOST_HANA_NAMESPACE_END
|
||||
|
||||
#endif // !BOOST_HANA_IS_EMPTY_HPP
|
||||
Reference in New Issue
Block a user