<unordered_map> operators unordered_map class unordered_multimap class <unordered_set> <utility> <valarray> <variant> <vector> C++ Standard Library overview C++ Standard Library containers Iterators Algorithms
再以unordered_map为例: 37/// Base types for unordered_map.38template<bool_Cache>39using__umap_traits=__detail::_Hashtable_traits<_Cache,false,true>;//non-const iterator unique_key4041template<typename_Key,42typename_Tp,43typename_Hash=hash<_Key>,//即 std::hash<>44typename_Pred=std::eq...
Non-member functions operator==operator!= (C++11)(C++11)(removed in C++20) compares the values in the unordered_map (function template) std::swap(std::unordered_map) (C++11) specializes thestd::swapalgorithm (function template) erase_if(std::unordered_map) ...
// unordered_map::empty#include <iostream>#include <unordered_map>intmain () { std::unordered_map<int,int> first; std::unordered_map<int,int> second = {{1,10},{2,20},{3,30}}; std::cout <<"first "<< (first.empty() ?"is empty":"is not empty") << std::endl; std::cou...
// clearing unordered_map#include <iostream>#include <string>#include <unordered_map>intmain () { std::unordered_map<std::string,std::string> mymap = { {"house","maison"}, {"car","voiture"}, {"grapefruit","pamplemousse"} }; std::cout <<"mymap contains:";for(auto& x: mymap...
<unordered_map> unordered_map unordered_multimap unordered_multimap unordered_multimap::~unordered_multimap unordered_multimap::unordered_multimap member functions: unordered_multimap::begin unordered_multimap::bucket unordered_multimap::bucket_count unordered_multimap::bucket_size unordered_multimap::cbegin ...
问使用自定义类类型作为键的C++ unordered_mapENunordered_map key无法取得时的的默认值 int main() { unordered_map<string, string> m1; unordered_map<string, bool> m2; unordered_map<string, int> m3; cout << (m1["a"] == "") << endl; // output 1 cout <<...
unordered_map::clear unordered_map::const_iterator unordered_map::const_local_iterator unordered_map::const_pointer unordered_map::const_reference unordered_map::count unordered_map::difference_type unordered_map::empty unordered_map::end unordered_map::equal_range ...
unordered_map中的key使用string还是int效率更高？先以24字节长度的字符串做key，生死10000个存在字典里面...
// unordered_multimap comparisons#include <iostream>#include <string>#include <unordered_map>typedefstd::unordered_multimap<std::string,int> stringmap;intmain () { stringmap a = { {"AAPL",100}, {"MSFT",200}, {"GOOG",50}, {"GOOG",20} }; stringmap b = { {"GOOG",20}, {"MSFT...