libcxx/test/std/numerics/numeric.ops/accumulate/accumulate.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 // <numeric>
  10
  11 // Became constexpr in C++20
  12 // template <InputIterator Iter, MoveConstructible T>
  13 //   requires HasPlus<T, Iter::reference>
  14 //         && HasAssign<T, HasPlus<T, Iter::reference>::result_type>
  15 //   T
  16 //   accumulate(Iter first, Iter last, T init);
  17
  18 #include <numeric>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22 #include "test_iterators.h"
  23
  24 template <class Iter, class T>
  25 TEST_CONSTEXPR_CXX20 void
  26 test(Iter first, Iter last, T init, T x)
  27 {
  28     assert(std::accumulate(first, last, init) == x);
  29 }
  30
  31 template <class Iter>
  32 TEST_CONSTEXPR_CXX20 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, 0);
  38     test(Iter(ia), Iter(ia), 10, 10);
  39     test(Iter(ia), Iter(ia+1), 0, 1);
  40     test(Iter(ia), Iter(ia+1), 10, 11);
  41     test(Iter(ia), Iter(ia+2), 0, 3);
  42     test(Iter(ia), Iter(ia+2), 10, 13);
  43     test(Iter(ia), Iter(ia+sa), 0, 21);
  44     test(Iter(ia), Iter(ia+sa), 10, 31);
  45 }
  46
  47 TEST_CONSTEXPR_CXX20 bool
  48 test()
  49 {
  50     test<cpp17_input_iterator<const int*> >();
  51     test<forward_iterator<const int*> >();
  52     test<bidirectional_iterator<const int*> >();
  53     test<random_access_iterator<const int*> >();
  54     test<const int*>();
  55
  56     return true;
  57 }
  58
  59 int main(int, char**)
  60 {
  61     test();
  62 #if TEST_STD_VER > 17
  63     static_assert(test());
  64 #endif
  65     return 0;
  66 }