/* @copyright Louis Dionne 2014 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 #include #include using namespace boost::hana; int main() { //! [main] BOOST_HANA_CONSTEXPR_LAMBDA auto double_ = [](auto x) { return x * 2; }; BOOST_HANA_CONSTEXPR_LAMBDA auto one_over = [](auto x) { return 1 / x; }; BOOST_HANA_STATIC_ASSERT(eval(fmap(double_, lazy(one_over)(4))) == 1 / 2); fmap(double_, lazy(one_over)(0)); // never evaluated //! [main] }