reserve.pass.cpp (2772B)
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 // <unordered_map> 11 12 // template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>, 13 // class Alloc = allocator<pair<const Key, T>>> 14 // class unordered_map 15 16 // void reserve(size_type n); 17 18 #include <unordered_map> 19 #include <string> 20 #include <cassert> 21 22 #include "test_macros.h" 23 #include "min_allocator.h" 24 25 template <class C> 26 void test(const C& c) 27 { 28 assert(c.size() == 4); 29 assert(c.at(1) == "one"); 30 assert(c.at(2) == "two"); 31 assert(c.at(3) == "three"); 32 assert(c.at(4) == "four"); 33 } 34 35 void reserve_invariant(size_t n) // LWG #2156 36 { 37 for (size_t i = 0; i < n; ++i) 38 { 39 std::unordered_map<size_t, size_t> c; 40 c.reserve(n); 41 size_t buckets = c.bucket_count(); 42 for (size_t j = 0; j < i; ++j) 43 { 44 c[i] = i; 45 assert(buckets == c.bucket_count()); 46 } 47 } 48 } 49 50 int main() 51 { 52 { 53 typedef std::unordered_map<int, std::string> C; 54 typedef std::pair<int, std::string> P; 55 P a[] = 56 { 57 P(1, "one"), 58 P(2, "two"), 59 P(3, "three"), 60 P(4, "four"), 61 P(1, "four"), 62 P(2, "four"), 63 }; 64 C c(a, a + sizeof(a)/sizeof(a[0])); 65 test(c); 66 assert(c.bucket_count() >= 5); 67 c.reserve(3); 68 LIBCPP_ASSERT(c.bucket_count() == 5); 69 test(c); 70 c.max_load_factor(2); 71 c.reserve(3); 72 assert(c.bucket_count() >= 2); 73 test(c); 74 c.reserve(31); 75 assert(c.bucket_count() >= 16); 76 test(c); 77 } 78 #if TEST_STD_VER >= 11 79 { 80 typedef std::unordered_map<int, std::string, std::hash<int>, std::equal_to<int>, 81 min_allocator<std::pair<const int, std::string>>> C; 82 typedef std::pair<int, std::string> P; 83 P a[] = 84 { 85 P(1, "one"), 86 P(2, "two"), 87 P(3, "three"), 88 P(4, "four"), 89 P(1, "four"), 90 P(2, "four"), 91 }; 92 C c(a, a + sizeof(a)/sizeof(a[0])); 93 test(c); 94 assert(c.bucket_count() >= 5); 95 c.reserve(3); 96 LIBCPP_ASSERT(c.bucket_count() == 5); 97 test(c); 98 c.max_load_factor(2); 99 c.reserve(3); 100 assert(c.bucket_count() >= 2); 101 test(c); 102 c.reserve(31); 103 assert(c.bucket_count() >= 16); 104 test(c); 105 } 106 #endif 107 reserve_invariant(20); 108 }