libcxx/test/std/numerics/complex.number/complex.value.ops/arg.pass.cpp

   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
   9 // <complex>
  10
  11 // template<class T>
  12 //   T
  13 //   arg(const complex<T>& x);
  14
  15 #include <complex>
  16 #include <cassert>
  17
  18 #include "test_macros.h"
  19 #include "../cases.h"
  20
  21 template <class T>
  22 void
  23 test()
  24 {
  25     std::complex<T> z(1, 0);
  26     assert(arg(z) == 0);
  27 }
  28
  29 void test_edges()
  30 {
  31     const double pi = std::atan2(+0., -0.);
  32     const unsigned N = sizeof(testcases) / sizeof(testcases[0]);
  33     for (unsigned i = 0; i < N; ++i)
  34     {
  35         double r = arg(testcases[i]);
  36         if (std::isnan(testcases[i].real()) || std::isnan(testcases[i].imag()))
  37             assert(std::isnan(r));
  38         else
  39         {
  40             switch (classify(testcases[i]))
  41             {
  42             case zero:
  43                 if (std::signbit(testcases[i].real()))
  44                 {
  45                     if (std::signbit(testcases[i].imag()))
  46                         is_about(r, -pi);
  47                     else
  48                         is_about(r, pi);
  49                 }
  50                 else
  51                 {
  52                     assert(std::signbit(testcases[i].imag()) == std::signbit(r));
  53                 }
  54                 break;
  55             case non_zero:
  56                 if (testcases[i].real() == 0)
  57                 {
  58                     if (testcases[i].imag() < 0)
  59                         is_about(r, -pi/2);
  60                     else
  61                         is_about(r, pi/2);
  62                 }
  63                 else if (testcases[i].imag() == 0)
  64                 {
  65                     if (testcases[i].real() < 0)
  66                     {
  67                         if (std::signbit(testcases[i].imag()))
  68                             is_about(r, -pi);
  69                         else
  70                             is_about(r, pi);
  71                     }
  72                     else
  73                     {
  74                         assert(r == 0);
  75                         assert(std::signbit(testcases[i].imag()) == std::signbit(r));
  76                     }
  77                 }
  78                 else if (testcases[i].imag() > 0)
  79                     assert(r > 0);
  80                 else
  81                     assert(r < 0);
  82                 break;
  83             case inf:
  84                 if (std::isinf(testcases[i].real()) && std::isinf(testcases[i].imag()))
  85                 {
  86                     if (testcases[i].real() < 0)
  87                     {
  88                         if (testcases[i].imag() > 0)
  89                             is_about(r, 0.75 * pi);
  90                         else
  91                             is_about(r, -0.75 * pi);
  92                     }
  93                     else
  94                     {
  95                         if (testcases[i].imag() > 0)
  96                             is_about(r, 0.25 * pi);
  97                         else
  98                             is_about(r, -0.25 * pi);
  99                     }
 100                 }
 101                 else if (std::isinf(testcases[i].real()))
 102                 {
 103                     if (testcases[i].real() < 0)
 104                     {
 105                         if (std::signbit(testcases[i].imag()))
 106                             is_about(r, -pi);
 107                         else
 108                             is_about(r, pi);
 109                     }
 110                     else
 111                     {
 112                         assert(r == 0);
 113                         assert(std::signbit(r) == std::signbit(testcases[i].imag()));
 114                     }
 115                 }
 116                 else
 117                 {
 118                     if (testcases[i].imag() < 0)
 119                         is_about(r, -pi/2);
 120                     else
 121                         is_about(r, pi/2);
 122                 }
 123                 break;
 124             }
 125         }
 126     }
 127 }
 128
 129 int main(int, char**)
 130 {
 131     test<float>();
 132     test<double>();
 133     test<long double>();
 134     test_edges();
 135
 136   return 0;
 137 }