null [re: spec#]

[Jonathan M Davis]

On Monday, November 08, 2010 15:23:40 Walter Bright wrote:
> dsimcha wrote:
> > While I'm also skeptical of the idea that simply declaring a variable can
> > cause arbitrarily complex code to be executed, I'll play Devil's
> > Advocate a little: What if we required the default struct constructor to
> > be nothrow?  We could also require some level of purity (at least weak
> > pure).
> 
> Not a bad idea, but this still leaves people nowhere who need non-trivial
> construction in order to have a valid object.

Well, if it's a default constructer which has to be nothrow and maybe pure or 
nothing, I'll take the default constructor. Now, if there's a better way to 
handle this which would result in full-blown, arbitrary default constructors, 
then that would be better, but something is better than nothing.

Another thought relates to the discussion of @disable on a struct's default 
constructor to disable init. What if we allowed default constructors but 
disabled init in the same way that we'd be doing with @disable? So, a struct 
uses init if it has no default constructor, but if it has one, then you can't 
use it where init would be required. Would that help fix things? It certainly 
would make some sense given that when using a default constructor, you don't 
really want init anyway. It could just be annoying with static arrays and the 
like (though = void should make it possible to make that work I think, if you 
really need to).

- Jonathan M Davis