Proposal for custom time string formatting in std.datetime

[Jonathan M Davis]

Okay. Assuming that I'm going to try and make TimeZone opaque within SysTime, 
does that require a pointer rather than a reference? And I assume then that 
the time zone stuff would need to be in a separate module than SysTime. That 
being the case, how would SysTime be able to use the time zone without 
importing that module? Does the C++ solution of forward declaring it like

class TimeZone;

work in D?

- Jonathan M Davis