xref: /llvm-project/libcxx/test/std/numerics/numeric.ops/reduce/reduce.pass.cpp (revision ecabb39ca11cba3d78a4134dfafd3bc0ee0473f4)
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 // <numeric>
10 // UNSUPPORTED: c++03, c++11, c++14
11 
12 // template<class InputIterator>
13 //     typename iterator_traits<InputIterator>::value_type
14 //     reduce(InputIterator first, InputIterator last);
15 
16 #include <numeric>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 #include "test_iterators.h"
21 
22 template <class Iter, class T>
23 void
24 test(Iter first, Iter last, T x)
25 {
26     static_assert( std::is_same_v<typename std::iterator_traits<decltype(first)>::value_type,
27                                 decltype(std::reduce(first, last))> );
28     assert(std::reduce(first, last) == x);
29 }
30 
31 template <class Iter>
32 void
33 test()
34 {
35     int ia[] = {1, 2, 3, 4, 5, 6};
36     unsigned sa = sizeof(ia) / sizeof(ia[0]);
37     test(Iter(ia), Iter(ia), 0);
38     test(Iter(ia), Iter(ia+1), 1);
39     test(Iter(ia), Iter(ia+2), 3);
40     test(Iter(ia), Iter(ia+sa), 21);
41 }
42 
43 template <typename T>
44 void test_return_type()
45 {
46     T *p = nullptr;
47     static_assert( std::is_same_v<T, decltype(std::reduce(p, p))> );
48 }
49 
50 int main(int, char**)
51 {
52     test_return_type<char>();
53     test_return_type<int>();
54     test_return_type<unsigned long>();
55     test_return_type<float>();
56     test_return_type<double>();
57 
58     test<input_iterator<const int*> >();
59     test<forward_iterator<const int*> >();
60     test<bidirectional_iterator<const int*> >();
61     test<random_access_iterator<const int*> >();
62     test<const int*>();
63 
64   return 0;
65 }
66