libcxx/test/std/algorithms/alg.modifying.operations/alg.partitions/partition.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<BidirectionalIterator Iter, Predicate<auto, Iter::value_type> Pred>
  12 //   requires ShuffleIterator<Iter>
  13 //         && CopyConstructible<Pred>
  14 //   constexpr Iter  // constexpr in C++20
  15 //   partition(Iter first, Iter last, Pred pred);
  16
  17 #include <algorithm>
  18 #include <cassert>
  19
  20
  21 #include "test_macros.h"
  22 #include "test_iterators.h"
  23
  24 struct is_odd
  25 {
  26     TEST_CONSTEXPR bool operator()(const int& i) const {return i & 1;}
  27 };
  28
  29 template <class Iter>
  30 TEST_CONSTEXPR_CXX20 bool
  31 test()
  32 {
  33     // check mixed
  34     int ia[] = {1, 2, 3, 4, 5, 6, 7, 8 ,9};
  35     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  36     Iter r = std::partition(Iter(ia), Iter(ia + sa), is_odd());
  37     assert(base(r) == ia + 5);
  38     for (int* i = ia; i < base(r); ++i)
  39         assert(is_odd()(*i));
  40     for (int* i = base(r); i < ia+sa; ++i)
  41         assert(!is_odd()(*i));
  42     // check empty
  43     r = std::partition(Iter(ia), Iter(ia), is_odd());
  44     assert(base(r) == ia);
  45     // check all false
  46     for (unsigned i = 0; i < sa; ++i)
  47         ia[i] = 2*i;
  48     r = std::partition(Iter(ia), Iter(ia+sa), is_odd());
  49     assert(base(r) == ia);
  50     // check all true
  51     for (unsigned i = 0; i < sa; ++i)
  52         ia[i] = 2*i+1;
  53     r = std::partition(Iter(ia), Iter(ia+sa), is_odd());
  54     assert(base(r) == ia+sa);
  55     // check all true but last
  56     for (unsigned i = 0; i < sa; ++i)
  57         ia[i] = 2*i+1;
  58     ia[sa-1] = 10;
  59     r = std::partition(Iter(ia), Iter(ia+sa), is_odd());
  60     assert(base(r) == ia+sa-1);
  61     for (int* i = ia; i < base(r); ++i)
  62         assert(is_odd()(*i));
  63     for (int* i = base(r); i < ia+sa; ++i)
  64         assert(!is_odd()(*i));
  65     // check all true but first
  66     for (unsigned i = 0; i < sa; ++i)
  67         ia[i] = 2*i+1;
  68     ia[0] = 10;
  69     r = std::partition(Iter(ia), Iter(ia+sa), is_odd());
  70     assert(base(r) == ia+sa-1);
  71     for (int* i = ia; i < base(r); ++i)
  72         assert(is_odd()(*i));
  73     for (int* i = base(r); i < ia+sa; ++i)
  74         assert(!is_odd()(*i));
  75     // check all false but last
  76     for (unsigned i = 0; i < sa; ++i)
  77         ia[i] = 2*i;
  78     ia[sa-1] = 11;
  79     r = std::partition(Iter(ia), Iter(ia+sa), is_odd());
  80     assert(base(r) == ia+1);
  81     for (int* i = ia; i < base(r); ++i)
  82         assert(is_odd()(*i));
  83     for (int* i = base(r); i < ia+sa; ++i)
  84         assert(!is_odd()(*i));
  85     // check all false but first
  86     for (unsigned i = 0; i < sa; ++i)
  87         ia[i] = 2*i;
  88     ia[0] = 11;
  89     r = std::partition(Iter(ia), Iter(ia+sa), is_odd());
  90     assert(base(r) == ia+1);
  91     for (int* i = ia; i < base(r); ++i)
  92         assert(is_odd()(*i));
  93     for (int* i = base(r); i < ia+sa; ++i)
  94         assert(!is_odd()(*i));
  95
  96     return true;
  97 }
  98
  99 int main(int, char**)
 100 {
 101     test<bidirectional_iterator<int*> >();
 102     test<random_access_iterator<int*> >();
 103     test<int*>();
 104
 105 #if TEST_STD_VER >= 20
 106     static_assert(test<bidirectional_iterator<int*>>());
 107     static_assert(test<random_access_iterator<int*>>());
 108     static_assert(test<int*>());
 109 #endif
 110
 111     return 0;
 112 }