61 lines
1.7 KiB
C++
61 lines
1.7 KiB
C++
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/*!
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@file
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Forward declares `boost::hana::insert`.
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@copyright Louis Dionne 2013-2016
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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*/
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#ifndef BOOST_HANA_FWD_INSERT_HPP
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#define BOOST_HANA_FWD_INSERT_HPP
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#include <boost/hana/config.hpp>
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#include <boost/hana/core/when.hpp>
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BOOST_HANA_NAMESPACE_BEGIN
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// Note: This function is documented per datatype/concept only.
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//! @cond
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template <typename T, typename = void>
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struct insert_impl : insert_impl<T, when<true>> { };
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//! @endcond
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struct insert_t {
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template <typename Set, typename ...Args>
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constexpr decltype(auto) operator()(Set&& set, Args&& ...args) const;
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};
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constexpr insert_t insert{};
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//! Insert a value at a given index in a sequence.
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//! @ingroup group-Sequence
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//!
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//! Given a sequence, an index and an element to insert, `insert` inserts
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//! the element at the given index.
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//!
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//! @param xs
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//! The sequence in which a value should be inserted.
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//!
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//! @param n
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//! The index at which an element should be inserted. This must be a
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//! non-negative `Constant` of an integral type, and it must also be
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//! true that `n < length(xs)` if `xs` is a finite sequence.
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//!
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//! @param element
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//! The element to insert in the sequence.
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//!
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//!
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//! Example
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//! -------
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//! @include example/insert.cpp
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#ifdef BOOST_HANA_DOXYGEN_INVOKED
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constexpr auto insert = [](auto&& xs, auto&& n, auto&& element) {
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return tag-dispatched;
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};
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#endif
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BOOST_HANA_NAMESPACE_END
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#endif // !BOOST_HANA_FWD_INSERT_HPP
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