#include <strstream>

std::ostrstream MYOUT(str, sizeof(str));

拼接字符串

 #include <iostream>
 #include <strstream>

 void main()
 {
     char str[] = {  };
     std::ostrstream MYOUT(str, sizeof(str));

     char str1[] = " world";

     MYOUT << "hello" << str1 << std::endl;//拼接字符串

     std::cout << MYOUT.str() << std::endl;//打印

     std::cout << str << std::endl;//打印

     system("pause");
 }