istream memory usage

[IWishIKnew]

How big does an stream object's buffer get? Is there a limit? In terms of there being multiple instances of the same stream, would each stream read from a file, or add the read data into it's own buffer before returning it?

Basically, do I have to worry about a bunch of istream objects becoming huge?

[Cubbi]

Depends on the buffer your stream is using:

If you keep writing to std::ostringstream, its std::stringbuf will grow as long as RAM allows.

If you keep writing to std::ofstream, its std::filebuf will be dumping its fixed-size buffer to the file each time it gets full.

If you're just reading, there is nothing to grow, normally.

[IWishIKnew]

Thanks.