max_element.pass.cpp (1663B)
1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <algorithm> 11 12 // template<ForwardIterator Iter> 13 // requires LessThanComparable<Iter::value_type> 14 // Iter 15 // max_element(Iter first, Iter last); 16 17 #include <algorithm> 18 #include <random> 19 #include <cassert> 20 21 #include "test_iterators.h" 22 23 std::mt19937 randomness; 24 25 template <class Iter> 26 void 27 test(Iter first, Iter last) 28 { 29 Iter i = std::max_element(first, last); 30 if (first != last) 31 { 32 for (Iter j = first; j != last; ++j) 33 assert(!(*i < *j)); 34 } 35 else 36 assert(i == last); 37 } 38 39 template <class Iter> 40 void 41 test(int N) 42 { 43 int* a = new int[N]; 44 for (int i = 0; i < N; ++i) 45 a[i] = i; 46 std::shuffle(a, a+N, randomness); 47 test(Iter(a), Iter(a+N)); 48 delete [] a; 49 } 50 51 template <class Iter> 52 void 53 test() 54 { 55 test<Iter>(0); 56 test<Iter>(1); 57 test<Iter>(2); 58 test<Iter>(3); 59 test<Iter>(10); 60 test<Iter>(1000); 61 } 62 63 #if TEST_STD_VER >= 14 64 constexpr int il[] = { 2, 4, 6, 8, 7, 5, 3, 1 }; 65 #endif 66 67 void constexpr_test() 68 { 69 #if TEST_STD_VER >= 14 70 constexpr auto p = std::max_element(il,il+8); 71 static_assert ( *p == 8, "" ); 72 #endif 73 } 74 75 int main() 76 { 77 test<forward_iterator<const int*> >(); 78 test<bidirectional_iterator<const int*> >(); 79 test<random_access_iterator<const int*> >(); 80 test<const int*>(); 81 82 constexpr_test (); 83 }