已经对C ++中的任何流类进行了复制构造函数和复制分配私人。这意味着，您无法复制 std :: ostringstream 对象：

Copy constructor and copy-assignment of any stream class in C++ has been made private. That means, you cannot make copy of std::ostringstream object:

std::ostringstream ss;

std::ostringstream ss1(ss); //not allowed - copy-constructor is private
ss1=ss; //not allowed - copy-assignment is private