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Diffstat (limited to '')
-rw-r--r-- | src/boost/libs/hana/example/scan_left.cpp | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/boost/libs/hana/example/scan_left.cpp b/src/boost/libs/hana/example/scan_left.cpp new file mode 100644 index 000000000..0e176ac13 --- /dev/null +++ b/src/boost/libs/hana/example/scan_left.cpp @@ -0,0 +1,39 @@ +// 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/scan_left.hpp> +#include <boost/hana/tuple.hpp> + +#include <sstream> +namespace hana = boost::hana; + + +auto to_string = [](auto x) { + std::ostringstream ss; + ss << x; + return ss.str(); +}; + +auto f = [](auto state, auto element) { + return "f(" + to_string(state) + ", " + to_string(element) + ")"; +}; + +int main() { + // with initial state + BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(2, "3", '4'), 1, f) == hana::make_tuple( + 1, + "f(1, 2)", + "f(f(1, 2), 3)", + "f(f(f(1, 2), 3), 4)" + )); + + // without initial state + BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(1, "2", '3'), f) == hana::make_tuple( + 1, + "f(1, 2)", + "f(f(1, 2), 3)" + )); +} |