>usingmap=std::map<Key, T, Compare, std::pmr::polymorphic_allocator<std::pair<constKey, T>>>; } (2)(since C++17) std::mapis a sorted associative container that contains key-value pairs with unique keys. Keys are sorted by using the comparison functionCompare. Search, removal, and in...
#include <map>#include <iostream>intmain(){std::map<int,std::string>c={{1,"one"},{2,"two"},{3,"three"},{4,"four"},{5,"five"},{6,"six"}};// 从 c 移除所有奇数for(autoit=c.begin();it!=c.end();){if(it->first%2!=0)it=c.erase(it);else++it;}for(auto&p:c)st...
getName().c_str() << std::endl; //equal_range std::pair<std::map<std::string, employee>::iterator, std::map<std::string, employee>::iterator> itrange; itrange = mapEmployee.equal_range(KEY_EMPLOYEE_K002); std::cout << "Equal_range: first = " << itrange.first->first.c_...
std::map<int,std::string>m{{1,"mango"},{2,"papaya"},{3,"guava"}};autonh=m.extract(2);nh.key()=4;m.insert(std::move(nh));// m == {{1, "mango"}, {3, "guava"}, {4, "papaya"}} 功能特性测试宏值标准功能特性
one of the simplest// options is to access the map via a constant reference.constauto&example2ref=example2;if(autosearch=example2ref.find(lk);search!=example2.end()){std::cout<<"Found "<<search->first.x<<' '<<search->second<<'\n';// search->second = 'c'; // error: assignme...
cbefore_begin Containers library Node handle operators (std::array) operators (std::deque) operators (std::forward_list) operators (std::list) operators (std::map) operators (std::multimap) operators (std::multiset) operators (std::queue) operators (std::set) operators (std::stack) operato...
{// 5this->operator=(that);that.moved=true;}~Map(){if(moved)return;deletea;deleteb;deletec...
first1['c'] =30; first1['d'] =40;map<char,int>first2( first1.begin(),first1.end() );map<char,int>first3( first2 ); map<char,int, classcomp> first4;///< class as Compare/** function pointer as Compare */bool(*fn_pt)(char,char) = fncomp;map<char,int,bool(*)(char,...
first['c']=50; first['d']=70; // 由一对范围迭代器指定输入 std::map<char,int> second (first.begin(), first.end()); // 复制构造 std::map<char,int> third (second); // 指定比较器:使用类 std::map<char, int, classcomp> fourth; // class as Compare ...
std::map 是有序键值对容器,它的元素的键是唯一的。用比较函数 Compare 排序键。搜索、移除和插入操作拥有对数复杂度。 map 通常实现为红黑树。 在每个标准库使用比较 (Compare) 概念的位置,以等价关系检验唯一性。不精确而言,若二个对象 a 与b 互相比较不小于对方 : !comp(a, b) && !comp(b, a) ,...