39 lines
1.1 KiB
C++
39 lines
1.1 KiB
C++
/*!
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@file
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Forward declares `boost::hana::fold`.
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@copyright Louis Dionne 2013-2017
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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_FOLD_HPP
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#define BOOST_HANA_FWD_FOLD_HPP
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#include <boost/hana/config.hpp>
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#include <boost/hana/fwd/fold_left.hpp>
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namespace boost { namespace hana {
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//! Equivalent to `fold_left`; provided for convenience.
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//! @ingroup group-Foldable
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//!
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//! `fold` is equivalent to `fold_left`. However, it is not tag-dispatched
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//! on its own because it is just an alias to `fold_left`. Also note that
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//! `fold` can be called with or without an initial state, just like
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//! `fold_left`:
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//!
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//! @code
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//! fold(xs, state, f) == fold_left(xs, state, f)
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//! fold(xs, f) == fold_left(xs, f)
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//! @endcode
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//!
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//!
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//! Example
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//! -------
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//! @include example/fold.cpp
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BOOST_HANA_INLINE_VARIABLE constexpr auto fold = fold_left;
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}} // end namespace boost::hana
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#endif // !BOOST_HANA_FWD_FOLD_HPP
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