{ return lhs.y < rhs.y; };std::map<Point,double, decltype(cmpLambda)>magy(cmpLambda);// 各种插入元素的方式:magy.insert(std::pair<Point,double>({5,-12},13));magy.insert({{3,4},5});magy.insert({Point{-8.0,-15.0},17});std::cout<<'\n';for(autop:magy)std::cout<<"The ...
} map <string, int, decltype(compFunc)*> mapWord3; //注意*号的存在。比较操作类型必须为函数指针类型 4、使用lambda表达式 auto fc = [](const string& str1, const string& str2) {return str1.compare(str2) > 0; }; map <string, int, decltype(fc)*> mapWord4; //同样要使用使用函数指...
1//所在头文件:<map>, std::map 类模板, std::map 通常由二叉搜索树实现。2template <classKey,//map::key_type3classT,//map::mapped_type4classCompare = less<Key>,//map::key_compare5classAlloc = allocator<pair<constKey,T> >//map::allocator_type6>classmap; std::unorder_map的定义如下:...
map(); explicit map( const Compare& comp, const Allocator& alloc = Allocator() ); (1) explicit map( const Allocator& alloc ); (1) (C++11 起) (2) template< class InputIt > map( InputIt first, InputIt last, const Compare& comp = Compare(), const Allocator& alloc = ...
{std::map<int,std::string>myMap;myMap[1]="One";myMap[2]="Two";myMap[3]="Three";int keyToFind=4;if(myMap.count(keyToFind)>0){std::cout<<"键 "<<keyToFind<<" 存在于 map 中。"<<std::endl;}else{std::cout<<"键 "<<keyToFind<<" 不存在于 map 中。"<<std::en...
map<Point,double, PointCmp>mag={{{5,-12},13},{{3,4},5},{{-8,-15},17}};std::cout<<"mag = "<<mag<<'\n';std::cout<<"Custom Key class option 2:\n";// Use a comparison lambda// This lambda sorts points according to their magnitudes, where// these magnitudes are taken ...
map(std::from_range_t, R&&rg, constAllocator&alloc) :map(std::from_range,std::forward<R>(rg), Compare(), alloc){} (13)(C++23 起) 从各种数据源构造新容器,可选地使用用户提供的分配器alloc或比较函数对象comp。 1-3)构造空容器。
1 #include<iostream> 2 #include<map> 3 using namespace std; 4 typedef struct tagIntPlus 5 { 6 int num,i; 7 }IntPlus; 8 //自定义比较规则 9 //注意operator是(),不是< 10 struct Cmp 11 { 12 bool operator () (IntPlus const &a,IntPlus const &b)const 13 { 14 if(a.num!=b....
{ // Different types : compare types identifiers return mapType<T>() < mapType<U>(); } template <typename T> bool operator()(const T& v1, const T& v2) const { // Same types : compare values return v1 < v2; } bool operator()(NoType, NoType) const { // No type (empty ...
/* > new Set(d.CXXConversionDecl.map(e=>JSON.stringify(e))) Set(22) { '["operator basic_string_view","__sv_type () const noexcept"]', '["operator long","streamoff () const"]', '["operator type-parameter-0-0","value_type () const noexcept"]', '["operator bool","value_...