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- /*!
- @file
- Forward declares `boost::hana::remove_range` and `boost::hana::remove_range_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_RANGE_HPP
- #define BOOST_HANA_FWD_REMOVE_RANGE_HPP
- #include <boost/hana/config.hpp>
- #include <boost/hana/core/when.hpp>
- #include <cstddef>
- BOOST_HANA_NAMESPACE_BEGIN
- //! Remove the elements inside a given range of indices from a sequence.
- //! @ingroup group-Sequence
- //!
- //! `remove_range` returns a new sequence identical to the original,
- //! except that elements at indices in the provided range are removed.
- //! Specifically, `remove_range([x0, ..., xn], from, to)` is a new
- //! sequence equivalent to `[x0, ..., x_from-1, x_to, ..., xn]`.
- //!
- //!
- //! @note
- //! The behavior is undefined if the range contains any index out of the
- //! bounds of the sequence.
- //!
- //!
- //! @param xs
- //! A sequence from which elements are removed.
- //!
- //! @param [from, to)
- //! An half-open interval of `IntegralConstant`s representing the indices
- //! of the elements to be removed from the sequence. The `IntegralConstant`s
- //! in the half-open interval must be non-negative and in the bounds of
- //! the sequence. The half-open interval must also be valid, meaning that
- //! `from <= to`.
- //!
- //!
- //! Example
- //! -------
- //! @include example/remove_range.cpp
- #ifdef BOOST_HANA_DOXYGEN_INVOKED
- constexpr auto remove_range = [](auto&& xs, auto const& from, auto const& to) {
- return tag-dispatched;
- };
- #else
- template <typename S, typename = void>
- struct remove_range_impl : remove_range_impl<S, when<true>> { };
- struct remove_range_t {
- template <typename Xs, typename From, typename To>
- constexpr auto operator()(Xs&& xs, From const& from, To const& to) const;
- };
- constexpr remove_range_t remove_range{};
- #endif
- //! Equivalent to `remove_range`; provided for convenience.
- //! @ingroup group-Sequence
- //!
- //!
- //! Example
- //! -------
- //! @include example/remove_range_c.cpp
- #ifdef BOOST_HANA_DOXYGEN_INVOKED
- template <std::size_t from, std::size_t to>
- constexpr auto remove_range_c = [](auto&& xs) {
- return hana::remove_range(forwarded(xs), hana::size_c<from>, hana::size_c<to>);
- };
- #else
- template <std::size_t from, std::size_t to>
- struct remove_range_c_t;
- template <std::size_t from, std::size_t to>
- constexpr remove_range_c_t<from, to> remove_range_c{};
- #endif
- BOOST_HANA_NAMESPACE_END
- #endif // !BOOST_HANA_FWD_REMOVE_RANGE_HPP
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