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Diffstat (limited to 'src/boost/libs/hana/example/struct/foldable.cpp')
-rw-r--r-- | src/boost/libs/hana/example/struct/foldable.cpp | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/struct/foldable.cpp b/src/boost/libs/hana/example/struct/foldable.cpp new file mode 100644 index 000000000..7f52e9203 --- /dev/null +++ b/src/boost/libs/hana/example/struct/foldable.cpp @@ -0,0 +1,31 @@ +// 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/define_struct.hpp> +#include <boost/hana/fold_left.hpp> +#include <boost/hana/second.hpp> +namespace hana = boost::hana; + + +struct Kitten { + BOOST_HANA_DEFINE_STRUCT(Kitten, + (int, extremely_cute), + (int, cute), + (int, not_so_cute) + ); +}; + +int main() { + constexpr Kitten kitten{5, 10, 0}; + + BOOST_HANA_CONSTEXPR_CHECK( + hana::fold_left(kitten, 0, [](auto total, auto member) { + // first(member) is the name of the member, here + // "extremely_cute", or "cute" or "not_so_cute", + // and second(member) is its value. + return hana::second(member) + total; + }) == (5 + 10 + 0) + ); +} |