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Diffstat (limited to 'boost/hana/fwd/fold.hpp')
| -rw-r--r-- | boost/hana/fwd/fold.hpp | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/boost/hana/fwd/fold.hpp b/boost/hana/fwd/fold.hpp new file mode 100644 index 0000000000..f34961d507 --- /dev/null +++ b/boost/hana/fwd/fold.hpp @@ -0,0 +1,38 @@ +/*! +@file +Forward declares `boost::hana::fold`. + +@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_FOLD_HPP +#define BOOST_HANA_FWD_FOLD_HPP + +#include <boost/hana/config.hpp> +#include <boost/hana/fwd/fold_left.hpp> + + +BOOST_HANA_NAMESPACE_BEGIN + //! Equivalent to `fold_left`; provided for convenience. + //! @ingroup group-Foldable + //! + //! `fold` is equivalent to `fold_left`. However, it is not tag-dispatched + //! on its own because it is just an alias to `fold_left`. Also note that + //! `fold` can be called with or without an initial state, just like + //! `fold_left`: + //! + //! @code + //! fold(xs, state, f) == fold_left(xs, state, f) + //! fold(xs, f) == fold_left(xs, f) + //! @endcode + //! + //! + //! Example + //! ------- + //! @include example/fold.cpp + constexpr auto fold = fold_left; +BOOST_HANA_NAMESPACE_END + +#endif // !BOOST_HANA_FWD_FOLD_HPP |