libcxx/test/std/algorithms/alg.nonmodifying/alg.search/search_n_pred.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<class ForwardIterator, class Size, class T, class BinaryPredicate>
  12 //   constexpr ForwardIterator     // constexpr after C++17
  13 //   search_n(ForwardIterator first, ForwardIterator last, Size count,
  14 //            const T& value, BinaryPredicate pred);
  15
  16 #include <algorithm>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20 #include "test_iterators.h"
  21 #include "user_defined_integral.h"
  22
  23 #if TEST_STD_VER > 17
  24 TEST_CONSTEXPR bool eq(int a, int b) { return a == b; }
  25
  26 TEST_CONSTEXPR bool test_constexpr() {
  27     int ia[] = {0, 0, 1, 1, 2, 2};
  28     return    (std::search_n(std::begin(ia), std::end(ia), 1, 0, eq) == ia)
  29            && (std::search_n(std::begin(ia), std::end(ia), 2, 1, eq) == ia+2)
  30            && (std::search_n(std::begin(ia), std::end(ia), 1, 3, eq) == std::end(ia))
  31            ;
  32     }
  33 #endif
  34
  35 struct count_equal
  36 {
  37     static unsigned count;
  38     template <class T>
  39     bool operator()(const T& x, const T& y)
  40         {++count; return x == y;}
  41 };
  42
  43 unsigned count_equal::count = 0;
  44
  45
  46 template <class Iter>
  47 void
  48 test()
  49 {
  50     int ia[] = {0, 1, 2, 3, 4, 5};
  51     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  52     count_equal::count = 0;
  53     assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 0, count_equal()) == Iter(ia));
  54     assert(count_equal::count <= sa);
  55     count_equal::count = 0;
  56     assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 0, count_equal()) == Iter(ia+0));
  57     assert(count_equal::count <= sa);
  58     count_equal::count = 0;
  59     assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 0, count_equal()) == Iter(ia+sa));
  60     assert(count_equal::count <= sa);
  61     count_equal::count = 0;
  62     assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 0, count_equal()) == Iter(ia+sa));
  63     assert(count_equal::count <= sa);
  64     count_equal::count = 0;
  65     assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 3, count_equal()) == Iter(ia));
  66     assert(count_equal::count <= sa);
  67     count_equal::count = 0;
  68     assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 3, count_equal()) == Iter(ia+3));
  69     assert(count_equal::count <= sa);
  70     count_equal::count = 0;
  71     assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 3, count_equal()) == Iter(ia+sa));
  72     assert(count_equal::count <= sa);
  73     count_equal::count = 0;
  74     assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 3, count_equal()) == Iter(ia+sa));
  75     assert(count_equal::count <= sa);
  76     count_equal::count = 0;
  77     assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 5, count_equal()) == Iter(ia));
  78     assert(count_equal::count <= sa);
  79     count_equal::count = 0;
  80     assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 5, count_equal()) == Iter(ia+5));
  81     assert(count_equal::count <= sa);
  82     count_equal::count = 0;
  83     assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 5, count_equal()) == Iter(ia+sa));
  84     assert(count_equal::count <= sa);
  85     count_equal::count = 0;
  86     assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 5, count_equal()) == Iter(ia+sa));
  87     assert(count_equal::count <= sa);
  88     count_equal::count = 0;
  89
  90     int ib[] = {0, 0, 1, 1, 2, 2};
  91     const unsigned sb = sizeof(ib)/sizeof(ib[0]);
  92     assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 0, count_equal()) == Iter(ib));
  93     assert(count_equal::count <= sb);
  94     count_equal::count = 0;
  95     assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 0, count_equal()) == Iter(ib+0));
  96     assert(count_equal::count <= sb);
  97     count_equal::count = 0;
  98     assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 0, count_equal()) == Iter(ib+0));
  99     assert(count_equal::count <= sb);
 100     count_equal::count = 0;
 101     assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 0, count_equal()) == Iter(ib+sb));
 102     assert(count_equal::count <= sb);
 103     count_equal::count = 0;
 104     assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 0, count_equal()) == Iter(ib+sb));
 105     assert(count_equal::count <= sb);
 106     count_equal::count = 0;
 107     assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 1, count_equal()) == Iter(ib));
 108     assert(count_equal::count <= sb);
 109     count_equal::count = 0;
 110     assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 1, count_equal()) == Iter(ib+2));
 111     assert(count_equal::count <= sb);
 112     count_equal::count = 0;
 113     assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 1, count_equal()) == Iter(ib+2));
 114     assert(count_equal::count <= sb);
 115     count_equal::count = 0;
 116     assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 1, count_equal()) == Iter(ib+sb));
 117     assert(count_equal::count <= sb);
 118     count_equal::count = 0;
 119     assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 1, count_equal()) == Iter(ib+sb));
 120     assert(count_equal::count <= sb);
 121     count_equal::count = 0;
 122     assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 2, count_equal()) == Iter(ib));
 123     assert(count_equal::count <= sb);
 124     count_equal::count = 0;
 125     assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 2, count_equal()) == Iter(ib+4));
 126     assert(count_equal::count <= sb);
 127     count_equal::count = 0;
 128     assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 2, count_equal()) == Iter(ib+4));
 129     assert(count_equal::count <= sb);
 130     count_equal::count = 0;
 131     assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 2, count_equal()) == Iter(ib+sb));
 132     assert(count_equal::count <= sb);
 133     count_equal::count = 0;
 134     assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 2, count_equal()) == Iter(ib+sb));
 135     assert(count_equal::count <= sb);
 136     count_equal::count = 0;
 137
 138     int ic[] = {0, 0, 0};
 139     const unsigned sc = sizeof(ic)/sizeof(ic[0]);
 140     assert(std::search_n(Iter(ic), Iter(ic+sc), 0, 0, count_equal()) == Iter(ic));
 141     assert(count_equal::count <= sc);
 142     count_equal::count = 0;
 143     assert(std::search_n(Iter(ic), Iter(ic+sc), 1, 0, count_equal()) == Iter(ic));
 144     assert(count_equal::count <= sc);
 145     count_equal::count = 0;
 146     assert(std::search_n(Iter(ic), Iter(ic+sc), 2, 0, count_equal()) == Iter(ic));
 147     assert(count_equal::count <= sc);
 148     count_equal::count = 0;
 149     assert(std::search_n(Iter(ic), Iter(ic+sc), 3, 0, count_equal()) == Iter(ic));
 150     assert(count_equal::count <= sc);
 151     count_equal::count = 0;
 152     assert(std::search_n(Iter(ic), Iter(ic+sc), 4, 0, count_equal()) == Iter(ic+sc));
 153     assert(count_equal::count <= sc);
 154     count_equal::count = 0;
 155
 156     // Check that we properly convert the size argument to an integral.
 157     TEST_IGNORE_NODISCARD std::search_n(Iter(ic), Iter(ic+sc), UserDefinedIntegral<unsigned>(4), 0, count_equal());
 158     count_equal::count = 0;
 159 }
 160
 161 int main(int, char**)
 162 {
 163     test<forward_iterator<const int*> >();
 164     test<bidirectional_iterator<const int*> >();
 165     test<random_access_iterator<const int*> >();
 166
 167 #if TEST_STD_VER > 17
 168     static_assert(test_constexpr());
 169 #endif
 170
 171   return 0;
 172 }