libcxx/test/std/algorithms/alg.sorting/alg.merge/merge.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 InIter1, InputIterator InIter2, typename OutIter>
  12 //   requires OutputIterator<OutIter, InIter1::reference>
  13 //         && OutputIterator<OutIter, InIter2::reference>
  14 //         && HasLess<InIter2::value_type, InIter1::value_type>
  15 //         && HasLess<InIter1::value_type, InIter2::value_type>
  16 //   constexpr OutIter       // constexpr after C++17
  17 //   merge(InIter1 first1, InIter1 last1, InIter2 first2, InIter2 last2,
  18 //         OutIter result);
  19
  20 #include <algorithm>
  21 #include <cassert>
  22
  23 #include "test_macros.h"
  24 #include "test_iterators.h"
  25 #include "../sortable_helpers.h"
  26
  27 template<class T, class Iter1, class Iter2, class OutIter>
  28 TEST_CONSTEXPR_CXX20 void test4()
  29 {
  30     const T a[] = {11, 33, 31, 41};
  31     const T b[] = {22, 32, 43, 42, 52};
  32     {
  33         T result[20] = {};
  34         T expected[] = {11, 22, 33, 31, 32, 41, 43, 42, 52};
  35         OutIter end = std::merge(Iter1(a), Iter1(a+4), Iter2(b), Iter2(b+5), OutIter(result));
  36         assert(std::lexicographical_compare(result, base(end), expected, expected+9, T::less) == 0);
  37         for (const T *it = base(end); it != result+20; ++it) {
  38             assert(it->value == 0);
  39         }
  40     }
  41     {
  42         T result[20] = {};
  43         T expected[] = {11, 22, 32, 33, 31, 43, 42, 41, 52};
  44         OutIter end = std::merge(Iter1(b), Iter1(b+5), Iter2(a), Iter2(a+4), OutIter(result));
  45         assert(std::lexicographical_compare(result, base(end), expected, expected+9, T::less) == 0);
  46         for (const T *it = base(end); it != result+20; ++it) {
  47             assert(it->value == 0);
  48         }
  49     }
  50 }
  51
  52 template<class T, class Iter1, class Iter2>
  53 TEST_CONSTEXPR_CXX20 void test3()
  54 {
  55     test4<T, Iter1, Iter2, cpp17_output_iterator<T*> >();
  56     test4<T, Iter1, Iter2, forward_iterator<T*> >();
  57     test4<T, Iter1, Iter2, bidirectional_iterator<T*> >();
  58     test4<T, Iter1, Iter2, random_access_iterator<T*> >();
  59     test4<T, Iter1, Iter2, T*>();
  60 }
  61
  62 template<class T, class Iter1>
  63 TEST_CONSTEXPR_CXX20 void test2()
  64 {
  65     test3<T, Iter1, cpp17_input_iterator<const T*> >();
  66     test3<T, Iter1, forward_iterator<const T*> >();
  67     test3<T, Iter1, bidirectional_iterator<const T*> >();
  68     test3<T, Iter1, random_access_iterator<const T*> >();
  69     test3<T, Iter1, const T*>();
  70 }
  71
  72 template<class T>
  73 TEST_CONSTEXPR_CXX20 void test1()
  74 {
  75     test2<T, cpp17_input_iterator<const T*> >();
  76     test2<T, forward_iterator<const T*> >();
  77     test2<T, bidirectional_iterator<const T*> >();
  78     test2<T, random_access_iterator<const T*> >();
  79     test2<T, const T*>();
  80 }
  81
  82 TEST_CONSTEXPR_CXX20 bool test()
  83 {
  84     test1<TrivialSortable>();
  85     test1<NonTrivialSortable>();
  86     return true;
  87 }
  88
  89 int main(int, char**)
  90 {
  91     test();
  92 #if TEST_STD_VER > 17
  93     static_assert(test());
  94 #endif
  95
  96     return 0;
  97 }