tests/bounded_ptr_src/arith.difference.cpp

   1 //
   2 // Tests for
   3 //  friend std::ptrdiff_t operator-(bounded_ptr const& a, bounded_ptr const& b);
   4 //  friend std::ptrdiff_t operator-(bounded_ptr const& a, T* b);
   5 //  friend std::ptrdiff_t operator-(T* a, bounded_ptr const& b);
   6 //
   7
   8 #include <libkern/c++/bounded_ptr.h>
   9 #include <array>
  10 #include <darwintest.h>
  11 #include <darwintest_utils.h>
  12 #include "test_utils.h"
  13
  14 #define _assert(...) T_ASSERT_TRUE((__VA_ARGS__), # __VA_ARGS__)
  15
  16 struct T {
  17         int i;
  18 };
  19
  20 template <typename Stored, typename Left, typename Right>
  21 static void
  22 tests()
  23 {
  24         std::array<Stored, 5> array = {Stored{0}, Stored{1}, Stored{2}, Stored{3}, Stored{4}};
  25
  26         // a >= b
  27         {
  28                 test_bounded_ptr<Left> const a(array.begin(), array.begin(), array.end());
  29                 test_bounded_ptr<Right> const b(array.begin(), array.begin(), array.end());
  30                 std::ptrdiff_t diff = a - b;
  31                 _assert(diff == 0);
  32         }
  33         {
  34                 test_bounded_ptr<Left> const a(array.begin() + 1, array.begin(), array.end());
  35                 test_bounded_ptr<Right> const b(array.begin(), array.begin(), array.end());
  36                 std::ptrdiff_t diff = a - b;
  37                 _assert(diff == 1);
  38         }
  39         {
  40                 test_bounded_ptr<Left> const a(array.begin() + 2, array.begin(), array.end());
  41                 test_bounded_ptr<Right> const b(array.begin(), array.begin(), array.end());
  42                 std::ptrdiff_t diff = a - b;
  43                 _assert(diff == 2);
  44         }
  45         {
  46                 test_bounded_ptr<Left> const a(array.begin() + 3, array.begin(), array.end());
  47                 test_bounded_ptr<Right> const b(array.begin(), array.begin(), array.end());
  48                 std::ptrdiff_t diff = a - b;
  49                 _assert(diff == 3);
  50         }
  51         {
  52                 test_bounded_ptr<Left> const a(array.begin() + 4, array.begin(), array.end());
  53                 test_bounded_ptr<Right> const b(array.begin(), array.begin(), array.end());
  54                 std::ptrdiff_t diff = a - b;
  55                 _assert(diff == 4);
  56         }
  57         {
  58                 test_bounded_ptr<Left> const a(array.end(), array.begin(), array.end());
  59                 test_bounded_ptr<Right> const b(array.begin(), array.begin(), array.end());
  60                 std::ptrdiff_t diff = a - b;
  61                 _assert(diff == 5);
  62         }
  63
  64         // a < b
  65         {
  66                 test_bounded_ptr<Left> const a(array.begin(), array.begin(), array.end());
  67                 test_bounded_ptr<Right> const b(array.begin() + 1, array.begin(), array.end());
  68                 std::ptrdiff_t diff = a - b;
  69                 _assert(diff == -1);
  70         }
  71         {
  72                 test_bounded_ptr<Left> const a(array.begin(), array.begin(), array.end());
  73                 test_bounded_ptr<Right> const b(array.begin() + 2, array.begin(), array.end());
  74                 std::ptrdiff_t diff = a - b;
  75                 _assert(diff == -2);
  76         }
  77         {
  78                 test_bounded_ptr<Left> const a(array.begin(), array.begin(), array.end());
  79                 test_bounded_ptr<Right> const b(array.begin() + 3, array.begin(), array.end());
  80                 std::ptrdiff_t diff = a - b;
  81                 _assert(diff == -3);
  82         }
  83         {
  84                 test_bounded_ptr<Left> const a(array.begin(), array.begin(), array.end());
  85                 test_bounded_ptr<Right> const b(array.begin() + 4, array.begin(), array.end());
  86                 std::ptrdiff_t diff = a - b;
  87                 _assert(diff == -4);
  88         }
  89         {
  90                 test_bounded_ptr<Left> const a(array.begin(), array.begin(), array.end());
  91                 test_bounded_ptr<Right> const b(array.begin() + 5, array.begin(), array.end());
  92                 std::ptrdiff_t diff = a - b;
  93                 _assert(diff == -5);
  94         }
  95
  96         // Subtract pointers with different bounds
  97         {
  98                 test_bounded_ptr<Left> const a(array.begin() + 2, array.begin() + 1, array.end() - 1);
  99                 test_bounded_ptr<Right> const b(array.begin() + 4, array.begin() + 3, array.end());
 100                 _assert(a - b == -2);
 101                 _assert(b - a == 2);
 102         }
 103
 104         // Subtract with raw pointers
 105         {
 106                 test_bounded_ptr<Left> const a(array.begin() + 2, array.begin() + 1, array.end() - 1);
 107                 Right* b = array.begin() + 4;
 108                 _assert(a - b == -2);
 109         }
 110         {
 111                 Left* a = array.begin() + 4;
 112                 test_bounded_ptr<Right> const b(array.begin() + 2, array.begin() + 1, array.end() - 1);
 113                 _assert(a - b == 2);
 114         }
 115 }
 116
 117 T_DECL(arith_difference, "bounded_ptr.arith.difference") {
 118         tests<T, T, T>();
 119         tests<T, T, T const>();
 120         tests<T, T const, T>();
 121         tests<T, T const, T const>();
 122 }