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 // <valarray>
10 
11 // template<class T> class valarray;
12 
13 // template<class T>
14 //   valarray<T>
15 //   atan2(const valarray<T>& x, const T& y);
16 
17 #include <valarray>
18 #include <cassert>
19 #include <sstream>
20 #include <cstddef>
21 
22 #include "test_macros.h"
23 
24 bool is_about(double x, double y, int p)
25 {
26     std::ostringstream o;
27     o.precision(p);
28     scientific(o);
29     o << x;
30     std::string a = o.str();
31     o.str("");
32     o << y;
33     return a == o.str();
34 }
35 
36 int main(int, char**)
37 {
38     {
39         typedef double T;
40         T a1[] = {-.9, -.5, 0., .5, .75};
41         T a3[] = {-8.7605805059819342e-01,
42                   -5.8800260354756750e-01,
43                    0.0000000000000000e+00,
44                    5.8800260354756750e-01,
45                    7.8539816339744828e-01};
46         const unsigned N = sizeof(a1)/sizeof(a1[0]);
47         std::valarray<T> v1(a1, N);
48         std::valarray<T> v3 = atan2(v1, .75);
49         assert(v3.size() == v1.size());
50         for (std::size_t i = 0; i < v3.size(); ++i)
51             assert(is_about(v3[i], a3[i], 10));
52     }
53 
54   return 0;
55 }
56