Edit: /usr/include/boost/hana/remove_at.hpp (2989B)
/*!
@file
Defines `boost::hana::remove_at` and `boost::hana::remove_at_c`.
@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_REMOVE_AT_HPP
#define BOOST_HANA_REMOVE_AT_HPP
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
BOOST_HANA_NAMESPACE_BEGIN
//! @cond
template
constexpr auto remove_at_t::operator()(Xs&& xs, N const& n) const {
using S = typename hana::tag_of::type;
using RemoveAt = BOOST_HANA_DISPATCH_IF(remove_at_impl,
hana::Sequence::value &&
hana::IntegralConstant::value
);
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
static_assert(hana::Sequence::value,
"hana::remove_at(xs, n) requires 'xs' to be a Sequence");
static_assert(hana::IntegralConstant::value,
"hana::remove_at(xs, n) requires 'n' to be an IntegralConstant");
#endif
static_assert(N::value >= 0,
"hana::remove_at(xs, n) requires 'n' to be non-negative");
return RemoveAt::apply(static_cast(xs), n);
}
//! @endcond
template
struct remove_at_impl> : default_ {
template
static constexpr auto
remove_at_helper(Xs&& xs, std::index_sequence,
std::index_sequence)
{
return hana::make(
hana::at_c(static_cast(xs))...,
hana::at_c(static_cast(xs))...
);
}
template
static constexpr auto apply(Xs&& xs, N const&) {
constexpr std::size_t n = N::value;
constexpr std::size_t len = decltype(hana::length(xs))::value;
static_assert(n < len,
"hana::remove_at(xs, n) requires 'n' to be in the bounds of the sequence");
return remove_at_helper(static_cast(xs),
std::make_index_sequence{},
std::make_index_sequence{});
}
};
template
struct remove_at_c_t {
template
constexpr decltype(auto) operator()(Xs&& xs) const
{ return hana::remove_at(static_cast(xs), hana::size_c); }
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_REMOVE_AT_HPP