size_type size() const noexcept; |
// unordered_set::size #include <iostream> #include <string> #include <unordered_set> int main () { std::unordered_set<std::string> myset; std::cout << "0. size: " << myset.size() << std::endl; myset = {"milk","potatoes","eggs"}; std::cout << "1. size: " << myset.size() << std::endl; myset.insert ("pineapple"); std::cout << "2. size: " << myset.size() << std::endl; myset.erase ("milk"); std::cout << "3. size: " << myset.size() << std::endl; return 0; } |
unordered_set::empty | 测试容器是否为空(公众成员函数) |
unordered_set::max_size | 返回最大元素个数(公众成员函数) |