File.size() is a ulong

[bearophile]

>From a recent update in File I've seen that size() returns an ulong, given by seek():
http://www.dsource.org/projects/phobos/browser/trunk/phobos/std/stdio.d?rev=2284#L585
http://www.dsource.org/projects/phobos/browser/trunk/phobos/std/stdio.d?rev=2284#L1245

It uses fseek, that seems to return a signed value:
http://www.cplusplus.com/reference/clibrary/cstdio/ftell/

Isn't it better and safer if those functions of File return a long instead of an ulong?

Bye,
bearophile