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
24struct is_odd
25{
26 TEST_CONSTEXPR bool operator()(const int& i) const {return i & 1;}
27};
28
29template <class Iter>
30TEST_CONSTEXPR_CXX20 bool
31test()
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
99int 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}
113

source code of libcxx/test/std/algorithms/alg.modifying.operations/alg.partitions/partition.pass.cpp