C++ 通过ostringstream 实现任意类型转string

#include <iostream>
#include <string>
using namespace std;
int main()
{
 int a = ;
 double b = 65.123;
 string str = "";
 //头文件是sstream
 std::ostringstream oss;
 oss << a << "---" << b;
 str = oss.str();
 cout << str << endl;
 return ;
}  

输出是56---65.123