1234567891011121314151617181920212223242526 |
- // 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/fold_left.hpp>
- #include <boost/hana/integral_constant.hpp>
- #include <boost/hana/plus.hpp>
- #include <boost/hana/string.hpp>
- #include <boost/hana/value.hpp>
- namespace hana = boost::hana;
- int main() {
- auto sum_string = [](auto str) {
- return hana::fold_left(str, hana::int_c<0>, [](auto sum, auto c) {
- constexpr int i = hana::value(c) - 48; // convert character to decimal
- return sum + hana::int_c<i>;
- });
- };
- BOOST_HANA_CONSTANT_CHECK(
- sum_string(BOOST_HANA_STRING("1234")) == hana::int_c<1 + 2 + 3 + 4>
- );
- }
|