advance.pass.cpp 2.7 KB

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  1. //===----------------------------------------------------------------------===//
  2. //
  3. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4. // See https://llvm.org/LICENSE.txt for license information.
  5. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6. //
  7. //===----------------------------------------------------------------------===//
  8. // <iterator>
  9. // All of these became constexpr in C++17
  10. //
  11. // template <InputIterator Iter>
  12. // constexpr void advance(Iter& i, Iter::difference_type n);
  13. //
  14. // template <BidirectionalIterator Iter>
  15. // constexpr void advance(Iter& i, Iter::difference_type n);
  16. //
  17. // template <RandomAccessIterator Iter>
  18. // constexpr void advance(Iter& i, Iter::difference_type n);
  19. #include <iterator>
  20. #include <cassert>
  21. #include "test_macros.h"
  22. #include "test_iterators.h"
  23. template <class It>
  24. void
  25. test(It i, typename std::iterator_traits<It>::difference_type n, It x)
  26. {
  27. std::advance(i, n);
  28. assert(i == x);
  29. }
  30. #if TEST_STD_VER > 14
  31. template <class It>
  32. constexpr bool
  33. constepxr_test(It i, typename std::iterator_traits<It>::difference_type n, It x)
  34. {
  35. std::advance(i, n);
  36. return i == x;
  37. }
  38. #endif
  39. int main(int, char**)
  40. {
  41. {
  42. const char* s = "1234567890";
  43. test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10));
  44. test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10));
  45. test(bidirectional_iterator<const char*>(s+5), 5, bidirectional_iterator<const char*>(s+10));
  46. test(bidirectional_iterator<const char*>(s+5), -5, bidirectional_iterator<const char*>(s));
  47. test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10));
  48. test(random_access_iterator<const char*>(s+5), -5, random_access_iterator<const char*>(s));
  49. test(s+5, 5, s+10);
  50. test(s+5, -5, s);
  51. }
  52. #if TEST_STD_VER > 14
  53. {
  54. constexpr const char* s = "1234567890";
  55. static_assert( constepxr_test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10)), "" );
  56. static_assert( constepxr_test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10)), "" );
  57. static_assert( constepxr_test(bidirectional_iterator<const char*>(s+5), 5, bidirectional_iterator<const char*>(s+10)), "" );
  58. static_assert( constepxr_test(bidirectional_iterator<const char*>(s+5), -5, bidirectional_iterator<const char*>(s)), "" );
  59. static_assert( constepxr_test(random_access_iterator<const char*>(s+5), 5, random_access_iterator<const char*>(s+10)), "" );
  60. static_assert( constepxr_test(random_access_iterator<const char*>(s+5), -5, random_access_iterator<const char*>(s)), "" );
  61. static_assert( constepxr_test(s+5, 5, s+10), "" );
  62. static_assert( constepxr_test(s+5, -5, s), "" );
  63. }
  64. #endif
  65. return 0;
  66. }