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

int main()
{
 int a = 55;
 double b = 65.123;
 string str = "";

 //頭文件是sstream
 ostringstream oss;
 oss << a << "---" << b;

 str = oss.str();
 cout << str << endl;
 return 0;
}