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/*!
@file
Forward declares `boost::hana::remove_at` and `boost::hana::remove_at_c`.
@copyright Louis Dionne 2013-2016
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_FWD_REMOVE_AT_HPP
#define BOOST_HANA_FWD_REMOVE_AT_HPP
#include <boost/hana/config.hpp>
#include <boost/hana/core/when.hpp>
#include <cstddef>
BOOST_HANA_NAMESPACE_BEGIN
//! Remove the element at a given index from a sequence.
//! @ingroup group-Sequence
//!
//! `remove_at` returns a new sequence identical to the original, except
//! that the element at the given index is removed. Specifically,
//! `remove_at([x0, ..., xn-1, xn, xn+1, ..., xm], n)` is a new
//! sequence equivalent to `[x0, ..., xn-1, xn+1, ..., xm]`.
//!
//! @note
//! The behavior is undefined if the index is out of the bounds of the
//! sequence.
//!
//!
//! @param xs
//! A sequence from which an element is to be removed.
//!
//! @param n
//! An non-negative `IntegralConstant` representing the index of the
//! element to be removed from the sequence. The behavior is undefined
//! if that index is not in the bounds of the sequence.
//!
//!
//! Example
//! -------
//! @include example/remove_at.cpp
#ifdef BOOST_HANA_DOXYGEN_INVOKED
constexpr auto remove_at = [](auto&& xs, auto const& n) {
return tag-dispatched;
};
#else
template <typename S, typename = void>
struct remove_at_impl : remove_at_impl<S, when<true>> { };
struct remove_at_t {
template <typename Xs, typename N>
constexpr auto operator()(Xs&& xs, N const& n) const;
};
constexpr remove_at_t remove_at{};
#endif
//! Equivalent to `remove_at`; provided for convenience.
//! @ingroup group-Sequence
//!
//!
//! Example
//! -------
//! @include example/remove_at_c.cpp
#ifdef BOOST_HANA_DOXYGEN_INVOKED
template <std::size_t n>
constexpr auto remove_at_c = [](auto&& xs) {
return hana::remove_at(forwarded(xs), hana::size_c<n>);
};
#else
template <std::size_t n>
struct remove_at_c_t;
template <std::size_t n>
constexpr remove_at_c_t<n> remove_at_c{};
#endif
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_FWD_REMOVE_AT_HPP
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