C++ 标准模板库STL--Pair

pair<size_t, size_t> 



#include <iostream>
#include <utility>
#include <cstdint>
#include <vector>

typedef std::pair<uint64_t, size_t> MapperKey;

int main(){
  std::vector<MapperKey> keys;

  MapperKey key1(123456789, 10);
  MapperKey key2(987654321, 20);
  MapperKey key3(555555555, 15);

  keys.push_back(key1);
  keys.push_back(key2);
  keys.push_back(key3);

  std::cout << "Iterating through MapperKeys:" << std::endl;
  for (const MapperKey& key : keys)
    {
      std::cout << "Key: " << key.first << ", " << key.second << std::endl;
    }

  return 0;
}

pair：用于存储两个 size_t 值组成的一对。

增：不能；

删：不能；

改：能，修改first和second的值；

查：能，修改first和second的值；