A replacement for std::tmpnam() ?

IIUC std::tmpnam() creates a filename that's guaranteed to be unique - but without creating an actual file (i.e. it returns a name that you could use if you wanted to...)

But (again IIUC) it only ever creates names that would be unique in your system's TEMP folder :(

Does anyone know of a function which can do the same thing but for some other folder (e.g. a folder that you pass to it?)