libcxx/test/std/algorithms/alg.modifying.operations/alg.generate/pstl.generate_n.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 // UNSUPPORTED: c++03, c++11, c++14
  10
  11 // UNSUPPORTED: libcpp-has-no-incomplete-pstl
  12
  13 // template<class ExecutionPolicy, class ForwardIterator, class Size, class Generator>
  14 //   ForwardIterator generate_n(ExecutionPolicy&& exec,
  15 //                              ForwardIterator first, Size n, Generator gen);
  16
  17 #include <algorithm>
  18 #include <cassert>
  19 #include <vector>
  20
  21 #include "test_iterators.h"
  22 #include "test_execution_policies.h"
  23 #include "type_algorithms.h"
  24
  25 template <class Iter>
  26 struct Test {
  27   template <class ExecutionPolicy>
  28   void operator()(ExecutionPolicy&& policy) {
  29     { // simple test
  30       int a[10];
  31       std::generate_n(policy, Iter(std::begin(a)), std::size(a), []() { return 1; });
  32       assert(std::all_of(std::begin(a), std::end(a), [](int i) { return i == 1; }));
  33     }
  34     { // empty range works
  35       int a[10] {3};
  36       std::generate_n(policy, Iter(std::begin(a)), 0, []() { return 1; });
  37       assert(a[0] == 3);
  38     }
  39     { // single-element range works
  40       int a[] {3};
  41       std::generate_n(policy, Iter(std::begin(a)), std::size(a), []() { return 5; });
  42       assert(a[0] == 5);
  43     }
  44     { // large range works
  45       std::vector<int> vec(150, 4);
  46       std::generate_n(policy, Iter(std::data(vec)), std::size(vec), []() { return 5; });
  47       assert(std::all_of(std::begin(vec), std::end(vec), [](int i) { return i == 5; }));
  48     }
  49   }
  50 };
  51
  52 int main(int, char**) {
  53   types::for_each(types::forward_iterator_list<int*>{}, TestIteratorWithPolicies<Test>{});
  54
  55   return 0;
  56 }