diff options
Diffstat (limited to 'src/boost/libs/hana/example/slice.cpp')
-rw-r--r-- | src/boost/libs/hana/example/slice.cpp | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/slice.cpp b/src/boost/libs/hana/example/slice.cpp new file mode 100644 index 000000000..954079312 --- /dev/null +++ b/src/boost/libs/hana/example/slice.cpp @@ -0,0 +1,43 @@ +// 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/core/to.hpp> +#include <boost/hana/equal.hpp> +#include <boost/hana/filter.hpp> +#include <boost/hana/integral_constant.hpp> +#include <boost/hana/length.hpp> +#include <boost/hana/mod.hpp> +#include <boost/hana/range.hpp> +#include <boost/hana/slice.hpp> +#include <boost/hana/tuple.hpp> +#include <boost/hana/type.hpp> +namespace hana = boost::hana; +using namespace hana::literals; + + +// Slice a contiguous range +constexpr auto xs = hana::make_tuple(0, '1', 2.2, 3_c, hana::type_c<float>); + +static_assert( + hana::slice(xs, hana::tuple_c<std::size_t, 1, 2, 3>) == + hana::make_tuple('1', 2.2, 3_c) +, ""); + + +// A more complex example with a non-contiguous range +constexpr auto letters = hana::to_tuple(hana::range_c<char, 'a', 'z'>); +constexpr auto indices = hana::to_tuple(hana::make_range(hana::size_c<0>, hana::length(letters))); + +auto even_indices = hana::filter(indices, [](auto n) { + return n % hana::size_c<2> == hana::size_c<0>; +}); + +BOOST_HANA_CONSTANT_CHECK( + hana::slice(letters, even_indices) == hana::tuple_c<char, + 'a', 'c', 'e', 'g', 'i', 'k', 'm', 'o', 'q', 's', 'u', 'w', 'y' + > +); + +int main() { } |