1 // Copyright Louis Dionne 2013-2017 2 // Distributed under the Boost Software License, Version 1.0. 3 // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) 4 5 #include <boost/hana/functional/placeholder.hpp> 6 namespace hana = boost::hana; 7 8 9 constexpr auto plus = hana::_ + hana::_; 10 static_assert(plus(1, 2) == 1 + 2, ""); 11 12 constexpr auto increment = hana::_ + 1; 13 static_assert(increment(1) == 2, ""); 14 15 constexpr auto twice = 2 * hana::_; 16 static_assert(twice(1) == 2, ""); 17 18 // Extra arguments are ignored. 19 static_assert(twice(1, "ignored") == 2, ""); 20 main()21int main() { } 22