1写set中元素的<构造符,但必须要求是const。猜想是因为set中对元素可能会有再继承或者封装处理,默认的比较函数是const operator<,所以必须要求const booloperator<(constCountry&b)const { returnm_nPopulation<b.m_nPopulation; } 2 单独写一个comparator,写一个新的函数类(结构也是类),并完成operator()函数,不...
From cppreference.com std::set Member functions set::set set::~set iterator find(constKey&key); (1) const_iterator find(constKey&key)const; (2) template<classK> iterator find(constK&x); (3)(since C++14) template<classK> const_iterator find(constK&x)const; ...
voidswap(set&other); (until C++17) voidswap(set&other)noexcept(/* see below */); (since C++17) Exchanges the contents of the container with those ofother. Does not invoke any move, copy, or swap operations on individual elements. ...
Cpp-std-set通过另一个类型查询 在Comparator里加上typedef std::true_type is_transparent;。原因主要是为了保持前向兼容。 #include<cassert>#include<set>classPoint{public:Point(intx,inty) :x(x),y(y) {}intx;inty; };structPointCmpY{// https://stackoverflow.com/questions/20317413/what-are-tran...
The comparator considers two elementsaandbequal ifa < b == falseandb < a == false In your case all elements are considered equal by the set since only the first element of each pair is compared a simple fix would be structcomp{booloperator()(constpair<int,int>&lhs,constpair<int,int>...
如果你查看编译器产生的错误，你会发现compare不可能是非静态函数。所以，通常你使用静态函数。但在你的...
std::set<std::pair<double, cv::Point>, QComparator> s; where QComparator is: struct QComparator { bool operator() (const std::pair<double, cv::Point>& lhs, const std::pair<double, cv::Point>& rhs) const { return lhs.first < rhs.first; ...
std::set有一个从key_compare类型到Compare的类型，所以简单地说：
// rlbond's magic comparator struct LessThan : public std::binary_function<BrokenOrder, BrokenOrder, bool> { bool operator()(const BrokenOrder& lhs, const BrokenOrder& rhs) const { return !(lhs == rhs) && (lhs < rhs); } }; ...
此实现不能工作。具有左侧或右侧int的2个比较器功能有错误的比较。