插入结构体时，emplace比insert少一次拷贝构造，推荐使用emplace

// map_emplace.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>
#include <map>
#include <string>
using namespace std;

struct Clinet {
	string host;
	int port;

	Clinet(string hostParam, int portParam):host(hostParam),port(portParam)	
	{
		cout << "Clinet Construct" << endl;
	}

	Clinet(const Clinet &other) :host(other.host), port(other.port)
	{
		cout << "Clinet Copy Construct" << endl;
	}
};

int main()
{
	map<int, struct Clinet> mapTmpVariable;
	mapTmpVariable.emplace(1, Clinet("192.168.100.1", 1000));
	mapTmpVariable.emplace(2, Clinet("192.168.100.2", 1001));
	mapTmpVariable.emplace(3, Clinet("192.168.100.3", 1002));
	cout << "size:" << mapTmpVariable.size() << endl;

	mapTmpVariable.insert(std::pair<int, struct Clinet>(4, Clinet("192.168.100.3", 1002)));
	cout << "size:" << mapTmpVariable.size() << endl;
}