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   static unsigned count;
  37   template <class T>
  38   bool operator()(const T& x, const T& y) const {
  39     ++count;
  40     return x == y;
  41   }
  42 };
  43
  44 unsigned count_equal::count = 0;
  45
  46
  47 template <class Iter>
  48 void
  49 test()
  50 {
  51     int ia[] = {0, 1, 2, 3, 4, 5};
  52     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  53     count_equal::count = 0;
  54     assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 0, count_equal()) == Iter(ia));
  55     assert(count_equal::count <= sa);
  56     count_equal::count = 0;
  57     assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 0, count_equal()) == Iter(ia+0));
  58     assert(count_equal::count <= sa);
  59     count_equal::count = 0;
  60     assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 0, count_equal()) == Iter(ia+sa));
  61     assert(count_equal::count <= sa);
  62     count_equal::count = 0;
  63     assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 0, count_equal()) == Iter(ia+sa));
  64     assert(count_equal::count <= sa);
  65     count_equal::count = 0;
  66     assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 3, count_equal()) == Iter(ia));
  67     assert(count_equal::count <= sa);
  68     count_equal::count = 0;
  69     assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 3, count_equal()) == Iter(ia+3));
  70     assert(count_equal::count <= sa);
  71     count_equal::count = 0;
  72     assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 3, count_equal()) == Iter(ia+sa));
  73     assert(count_equal::count <= sa);
  74     count_equal::count = 0;
  75     assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 3, count_equal()) == Iter(ia+sa));
  76     assert(count_equal::count <= sa);
  77     count_equal::count = 0;
  78     assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 5, count_equal()) == Iter(ia));
  79     assert(count_equal::count <= sa);
  80     count_equal::count = 0;
  81     assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 5, count_equal()) == Iter(ia+5));
  82     assert(count_equal::count <= sa);
  83     count_equal::count = 0;
  84     assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 5, count_equal()) == Iter(ia+sa));
  85     assert(count_equal::count <= sa);
  86     count_equal::count = 0;
  87     assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 5, count_equal()) == Iter(ia+sa));
  88     assert(count_equal::count <= sa);
  89     count_equal::count = 0;
  90
  91     int ib[] = {0, 0, 1, 1, 2, 2};
  92     const unsigned sb = sizeof(ib)/sizeof(ib[0]);
  93     assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 0, count_equal()) == Iter(ib));
  94     assert(count_equal::count <= sb);
  95     count_equal::count = 0;
  96     assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 0, count_equal()) == Iter(ib+0));
  97     assert(count_equal::count <= sb);
  98     count_equal::count = 0;
  99     assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 0, count_equal()) == Iter(ib+0));
 100     assert(count_equal::count <= sb);
 101     count_equal::count = 0;
 102     assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 0, count_equal()) == Iter(ib+sb));
 103     assert(count_equal::count <= sb);
 104     count_equal::count = 0;
 105     assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 0, count_equal()) == Iter(ib+sb));
 106     assert(count_equal::count <= sb);
 107     count_equal::count = 0;
 108     assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 1, count_equal()) == Iter(ib));
 109     assert(count_equal::count <= sb);
 110     count_equal::count = 0;
 111     assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 1, count_equal()) == Iter(ib+2));
 112     assert(count_equal::count <= sb);
 113     count_equal::count = 0;
 114     assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 1, count_equal()) == Iter(ib+2));
 115     assert(count_equal::count <= sb);
 116     count_equal::count = 0;
 117     assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 1, count_equal()) == Iter(ib+sb));
 118     assert(count_equal::count <= sb);
 119     count_equal::count = 0;
 120     assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 1, count_equal()) == Iter(ib+sb));
 121     assert(count_equal::count <= sb);
 122     count_equal::count = 0;
 123     assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 2, count_equal()) == Iter(ib));
 124     assert(count_equal::count <= sb);
 125     count_equal::count = 0;
 126     assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 2, count_equal()) == Iter(ib+4));
 127     assert(count_equal::count <= sb);
 128     count_equal::count = 0;
 129     assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 2, count_equal()) == Iter(ib+4));
 130     assert(count_equal::count <= sb);
 131     count_equal::count = 0;
 132     assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 2, count_equal()) == Iter(ib+sb));
 133     assert(count_equal::count <= sb);
 134     count_equal::count = 0;
 135     assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 2, count_equal()) == Iter(ib+sb));
 136     assert(count_equal::count <= sb);
 137     count_equal::count = 0;
 138
 139     int ic[] = {0, 0, 0};
 140     const unsigned sc = sizeof(ic)/sizeof(ic[0]);
 141     assert(std::search_n(Iter(ic), Iter(ic+sc), 0, 0, count_equal()) == Iter(ic));
 142     assert(count_equal::count <= sc);
 143     count_equal::count = 0;
 144     assert(std::search_n(Iter(ic), Iter(ic+sc), 1, 0, count_equal()) == Iter(ic));
 145     assert(count_equal::count <= sc);
 146     count_equal::count = 0;
 147     assert(std::search_n(Iter(ic), Iter(ic+sc), 2, 0, count_equal()) == Iter(ic));
 148     assert(count_equal::count <= sc);
 149     count_equal::count = 0;
 150     assert(std::search_n(Iter(ic), Iter(ic+sc), 3, 0, count_equal()) == Iter(ic));
 151     assert(count_equal::count <= sc);
 152     count_equal::count = 0;
 153     assert(std::search_n(Iter(ic), Iter(ic+sc), 4, 0, count_equal()) == Iter(ic+sc));
 154     assert(count_equal::count <= sc);
 155     count_equal::count = 0;
 156
 157     // Check that we properly convert the size argument to an integral.
 158     TEST_IGNORE_NODISCARD std::search_n(Iter(ic), Iter(ic+sc), UserDefinedIntegral<unsigned>(4), 0, count_equal());
 159     count_equal::count = 0;
 160 }
 161
 162 class A {
 163 public:
 164   A(int x, int y) : x_(x), y_(y) {}
 165   int x() const { return x_; }
 166   int y() const { return y_; }
 167
 168 private:
 169   int x_;
 170   int y_;
 171 };
 172
 173 struct Pred {
 174   bool operator()(const A& l, int r) const { return l.x() == r; }
 175 };
 176
 177 int main(int, char**)
 178 {
 179     test<forward_iterator<const int*> >();
 180     test<bidirectional_iterator<const int*> >();
 181     test<random_access_iterator<const int*> >();
 182
 183     // test bug reported in https://reviews.llvm.org/D124079?#3661721
 184     {
 185         A a[]       = {A(1, 2), A(2, 3), A(2, 4)};
 186         int value   = 2;
 187         auto result = std::search_n(a, a + 3, 1, value, Pred());
 188         assert(result == a + 1);
 189     }
 190
 191 #if TEST_STD_VER > 17
 192     static_assert(test_constexpr());
 193 #endif
 194
 195   return 0;
 196 }