mp_reverse_fold.cpp 2.8 KB

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  1. // Copyright 2015-2017 Peter Dimov.
  2. //
  3. // Distributed under the Boost Software License, Version 1.0.
  4. //
  5. // See accompanying file LICENSE_1_0.txt or copy at
  6. // http://www.boost.org/LICENSE_1_0.txt
  7. #include <boost/mp11/algorithm.hpp>
  8. #include <boost/mp11/list.hpp>
  9. #include <boost/mp11/integral.hpp>
  10. #include <boost/core/lightweight_test_trait.hpp>
  11. #include <type_traits>
  12. #include <tuple>
  13. struct X1 {};
  14. struct X2 {};
  15. struct X3 {};
  16. struct X4 {};
  17. template<class T1, class T2> struct F {};
  18. using boost::mp11::mp_push_back;
  19. using boost::mp11::mp_push_front;
  20. template<class T, class L> using rev_push_back = mp_push_back<L, T>;
  21. template<class T, class L> using rev_push_front = mp_push_front<L, T>;
  22. using boost::mp11::mp_plus;
  23. int main()
  24. {
  25. using boost::mp11::mp_list;
  26. using boost::mp11::mp_reverse_fold;
  27. {
  28. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<mp_list<>, void, F>, void>));
  29. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<mp_list<X1>, void, F>, F<X1, void>>));
  30. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<mp_list<X1, X2>, void, F>, F<X1, F<X2, void>>>));
  31. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<mp_list<X1, X2, X3>, void, F>, F<X1, F<X2, F<X3, void>>>>));
  32. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<mp_list<X1, X2, X3, X4>, void, F>, F<X1, F<X2, F<X3, F<X4, void>>>>>));
  33. }
  34. {
  35. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<std::tuple<>, void, F>, void>));
  36. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<std::tuple<X1>, void, F>, F<X1, void>>));
  37. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<std::tuple<X1, X2>, void, F>, F<X1, F<X2, void>>>));
  38. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<std::tuple<X1, X2, X3>, void, F>, F<X1, F<X2, F<X3, void>>>>));
  39. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<std::tuple<X1, X2, X3, X4>, void, F>, F<X1, F<X2, F<X3, F<X4, void>>>>>));
  40. }
  41. {
  42. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<std::tuple<X1, X2, X3, X4>, mp_list<>, rev_push_back>, mp_list<X4, X3, X2, X1>>));
  43. }
  44. {
  45. BOOST_TEST_TRAIT_TRUE((std::is_same<mp_reverse_fold<std::tuple<X1, X2, X3, X4>, mp_list<>, rev_push_front>, mp_list<X1, X2, X3, X4>>));
  46. }
  47. using boost::mp11::mp_iota_c;
  48. using boost::mp11::mp_reverse;
  49. using boost::mp11::mp_size_t;
  50. {
  51. int const N = 37;
  52. using L = mp_iota_c<N>;
  53. using R1 = mp_reverse_fold<L, mp_list<>, rev_push_front>;
  54. BOOST_TEST_TRAIT_TRUE((std::is_same<R1, L>));
  55. using R2 = mp_reverse_fold<L, mp_list<>, rev_push_back>;
  56. BOOST_TEST_TRAIT_TRUE((std::is_same<R2, mp_reverse<L>>));
  57. using R3 = mp_reverse_fold<L, mp_size_t<0>, mp_plus>;
  58. BOOST_TEST_TRAIT_TRUE((std::is_same<R3, mp_size_t<N*(N-1)/2>>));
  59. }
  60. return boost::report_errors();
  61. }