libcxx/test/std/algorithms/alg.modifying.operations/alg.transform/unary_transform.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<InputIterator InIter, class OutIter,
  12 //          Callable<auto, const InIter::value_type&> Op>
  13 //   requires OutputIterator<OutIter, Op::result_type> && CopyConstructible<Op>
  14 // constexpr OutIter      // constexpr after C++17
  15 //   transform(InIter first, InIter last, OutIter result, Op op);
  16
  17 #include <algorithm>
  18 #include <functional>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22 #include "test_iterators.h"
  23
  24 TEST_CONSTEXPR int plusOne(int v) { return v + 1; }
  25
  26
  27 #if TEST_STD_VER > 17
  28 TEST_CONSTEXPR bool test_constexpr() {
  29     int ia[] = {1, 3, 6, 7};
  30     int ib[] = {0, 0, 0, 0, 0}; // one bigger
  31     const int expected[] = {2, 4, 7, 8};
  32
  33     auto it = std::transform(std::begin(ia), std::end(ia), std::begin(ib), plusOne);
  34
  35     return it == (std::begin(ib) + std::size(ia))
  36         && *it == 0 // don't overwrite the last value in the output array
  37         && std::equal(std::begin(ib), it, std::begin(expected), std::end(expected))
  38         ;
  39     }
  40 #endif
  41
  42
  43 template <class InIter, class OutIter>
  44 void
  45 test()
  46 {
  47     int ia[] = {0, 1, 2, 3, 4};
  48     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  49     int ib[sa] = {0};
  50     OutIter r = std::transform(InIter(ia), InIter(ia+sa),
  51                                OutIter(ib), plusOne);
  52     assert(base(r) == ib + sa);
  53     assert(ib[0] == 1);
  54     assert(ib[1] == 2);
  55     assert(ib[2] == 3);
  56     assert(ib[3] == 4);
  57     assert(ib[4] == 5);
  58 }
  59
  60 int main(int, char**)
  61 {
  62     test<input_iterator<const int*>, output_iterator<int*> >();
  63     test<input_iterator<const int*>, input_iterator<int*> >();
  64     test<input_iterator<const int*>, forward_iterator<int*> >();
  65     test<input_iterator<const int*>, bidirectional_iterator<int*> >();
  66     test<input_iterator<const int*>, random_access_iterator<int*> >();
  67     test<input_iterator<const int*>, int*>();
  68
  69     test<forward_iterator<const int*>, output_iterator<int*> >();
  70     test<forward_iterator<const int*>, input_iterator<int*> >();
  71     test<forward_iterator<const int*>, forward_iterator<int*> >();
  72     test<forward_iterator<const int*>, bidirectional_iterator<int*> >();
  73     test<forward_iterator<const int*>, random_access_iterator<int*> >();
  74     test<forward_iterator<const int*>, int*>();
  75
  76     test<bidirectional_iterator<const int*>, output_iterator<int*> >();
  77     test<bidirectional_iterator<const int*>, input_iterator<int*> >();
  78     test<bidirectional_iterator<const int*>, forward_iterator<int*> >();
  79     test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >();
  80     test<bidirectional_iterator<const int*>, random_access_iterator<int*> >();
  81     test<bidirectional_iterator<const int*>, int*>();
  82
  83     test<random_access_iterator<const int*>, output_iterator<int*> >();
  84     test<random_access_iterator<const int*>, input_iterator<int*> >();
  85     test<random_access_iterator<const int*>, forward_iterator<int*> >();
  86     test<random_access_iterator<const int*>, bidirectional_iterator<int*> >();
  87     test<random_access_iterator<const int*>, random_access_iterator<int*> >();
  88     test<random_access_iterator<const int*>, int*>();
  89
  90     test<const int*, output_iterator<int*> >();
  91     test<const int*, input_iterator<int*> >();
  92     test<const int*, forward_iterator<int*> >();
  93     test<const int*, bidirectional_iterator<int*> >();
  94     test<const int*, random_access_iterator<int*> >();
  95     test<const int*, int*>();
  96
  97 #if TEST_STD_VER > 17
  98     static_assert(test_constexpr());
  99 #endif
 100
 101   return 0;
 102 }