length.cpp 1.6 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/equal.hpp>
  6. #include <boost/hana/experimental/view.hpp>
  7. #include <boost/hana/integral_constant.hpp>
  8. #include <boost/hana/length.hpp>
  9. #include <support/seq.hpp>
  10. namespace hana = boost::hana;
  11. template <int> struct undefined { };
  12. int main() {
  13. auto container = ::seq;
  14. {
  15. auto storage = container();
  16. auto transformed = hana::experimental::transformed(storage, undefined<99>{});
  17. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  18. hana::length(transformed),
  19. hana::size_c<0>
  20. ));
  21. }{
  22. auto storage = container(undefined<0>{});
  23. auto transformed = hana::experimental::transformed(storage, undefined<99>{});
  24. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  25. hana::length(transformed),
  26. hana::size_c<1>
  27. ));
  28. }{
  29. auto storage = container(undefined<0>{}, undefined<1>{});
  30. auto transformed = hana::experimental::transformed(storage, undefined<99>{});
  31. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  32. hana::length(transformed),
  33. hana::size_c<2>
  34. ));
  35. }{
  36. auto storage = container(undefined<0>{}, undefined<1>{}, undefined<2>{});
  37. auto transformed = hana::experimental::transformed(storage, undefined<99>{});
  38. BOOST_HANA_CONSTANT_CHECK(hana::equal(
  39. hana::length(transformed),
  40. hana::size_c<3>
  41. ));
  42. }
  43. }