On exceptions in D

[Dmitry Olshansky]

Oops, I've meant to reply to this post:

 >
 > I didn't intend to imply compile-time construction, just statically
 > allocate `ubyte[__traits(classInstanceSize, Ex)]` and lazily emplace
 > `Ex` there instead of GC-allocating with `new`. It would be doable with
 > `std.typecons.Scoped` if that type wasn't naively anonymized a couple of
 > releases ago.

I thought of this for a while and I think lazly dynamic allocation is 
still better. First things first - there is still lazy initialization 
both ways.

The only potential gain of statically allocating memory here is on the 
first exception being thrown, which doesn't gain anything for our prime 
case of "many exceptions".

Lastly if the said exception is never thrown, static allocation would 
waste more memory of each thread (TLS). This is especially true for 
cases where not every thread runs the same code (which is not a small 
part of the landscape).



-- 
Dmitry Olshansky