find_if.cpp 1.2 KB

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  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. #include <boost/hana/assert.hpp>
  5. #include <boost/hana/bool.hpp>
  6. #include <boost/hana/equal.hpp>
  7. #include <boost/hana/find_if.hpp>
  8. #include <boost/hana/functional/always.hpp>
  9. #include <boost/hana/integral_constant.hpp>
  10. #include <boost/hana/optional.hpp>
  11. #include <boost/hana/string.hpp>
  12. namespace hana = boost::hana;
  13. int main() {
  14. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  15. hana::find_if(BOOST_HANA_STRING(""), hana::always(hana::true_c)),
  16. hana::nothing
  17. ));
  18. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  19. hana::find_if(BOOST_HANA_STRING("abcd"), hana::equal.to(hana::char_c<'a'>)),
  20. hana::just(hana::char_c<'a'>)
  21. ));
  22. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  23. hana::find_if(BOOST_HANA_STRING("abcd"), hana::equal.to(hana::char_c<'c'>)),
  24. hana::just(hana::char_c<'c'>)
  25. ));
  26. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  27. hana::find_if(BOOST_HANA_STRING("abcd"), hana::equal.to(hana::char_c<'d'>)),
  28. hana::just(hana::char_c<'d'>)
  29. ));
  30. }