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