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Diffstat (limited to 'src/boost/libs/hana/example/unfold_right.cpp')
-rw-r--r-- | src/boost/libs/hana/example/unfold_right.cpp | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/unfold_right.cpp b/src/boost/libs/hana/example/unfold_right.cpp new file mode 100644 index 00000000..f4599ddc --- /dev/null +++ b/src/boost/libs/hana/example/unfold_right.cpp @@ -0,0 +1,28 @@ +// 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) + +#include <boost/hana/assert.hpp> +#include <boost/hana/equal.hpp> +#include <boost/hana/if.hpp> +#include <boost/hana/integral_constant.hpp> +#include <boost/hana/minus.hpp> +#include <boost/hana/optional.hpp> +#include <boost/hana/pair.hpp> +#include <boost/hana/tuple.hpp> +#include <boost/hana/unfold_right.hpp> +namespace hana = boost::hana; + + +BOOST_HANA_CONSTANT_CHECK( + hana::unfold_right<hana::tuple_tag>(hana::int_c<10>, [](auto x) { + return hana::if_(x == hana::int_c<0>, + hana::nothing, + hana::just(hana::make_pair(x, x - hana::int_c<1>)) + ); + }) + == + hana::tuple_c<int, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1> +); + +int main() { } |