libcxx/test/std/algorithms/alg.modifying.operations/alg.generate/generate.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 // <algorithm>
  10
  11 // template<ForwardIterator Iter, Callable Generator>
  12 //   requires OutputIterator<Iter, Generator::result_type>
  13 //         && CopyConstructible<Generator>
  14 //   constexpr void      // constexpr after c++17
  15 //   generate(Iter first, Iter last, Generator gen);
  16
  17 #include <algorithm>
  18 #include <cassert>
  19
  20 #include "test_macros.h"
  21 #include "test_iterators.h"
  22
  23 struct gen_test
  24 {
  25     TEST_CONSTEXPR int operator()() const {return 1;}
  26 };
  27
  28
  29 #if TEST_STD_VER > 17
  30 TEST_CONSTEXPR bool test_constexpr() {
  31     int ia[] = {0, 1, 2, 3, 4};
  32
  33     std::generate(std::begin(ia), std::end(ia), gen_test());
  34
  35     return std::all_of(std::begin(ia), std::end(ia), [](int x) { return x == 1; })
  36         ;
  37     }
  38 #endif
  39
  40
  41 template <class Iter>
  42 void
  43 test()
  44 {
  45     const unsigned n = 4;
  46     int ia[n] = {0};
  47     std::generate(Iter(ia), Iter(ia+n), gen_test());
  48     assert(ia[0] == 1);
  49     assert(ia[1] == 1);
  50     assert(ia[2] == 1);
  51     assert(ia[3] == 1);
  52 }
  53
  54 int main(int, char**)
  55 {
  56     test<forward_iterator<int*> >();
  57     test<bidirectional_iterator<int*> >();
  58     test<random_access_iterator<int*> >();
  59     test<int*>();
  60
  61 #if TEST_STD_VER > 17
  62     static_assert(test_constexpr());
  63 #endif
  64
  65   return 0;
  66 }