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- /*!
- @file
- Forward declares `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_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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