Your organization may make its own. Such an implementation might use the plus sign for concatenation. A string steam is a stream that writes to a string instead of a file. You can declare it without giving a maximum length, and you can keep appending strings to it. If you have a local instance of a class with a large buffer or lots of small variables, and you declare it as a local variable, you could use up your stack and cause the program to act erratically, probably at some other point in the program.
Stack is cool.
Don't Make This Bonehead Mistake I occasionally make this goof. I forget the local variable is on the stack, and pass a pointer to that local variable it back as the function return. If the code using the returned pointer doesn't write to that pointer's contents, this won't crash the program. However, sometimes, depending on the memory map, the returned value will magically change as something else on the stack overwrites the now out of scope variable. This subject rates a page of its own.