safer casts - take II

[BCS]

Reply to Dee,

> BCS Wrote:
> 
>> Reply to Yigal,
>> 
>>> I don't add this to the "official" proposal yet, this is still just
>>> some
>>> thoughts not finalized into anything formal.
>>> feel free to discuss this and propose names for the strong_cast!(T)
>>> template.
>> force_cast!(T)
>> 
>> and I'd put them in object.d
>> 
> What is object.d please?

all the stuff that you can't live without like the definition of Object, 
TypeInfo 'n friends, the Error and Exception class and whatnot.