ceph/src/boost/libs/hana/example/functional/placeholder.cpp

   1 // Copyright Louis Dionne 2013-2016
   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
  21 int main() { }