[:] as empty associative array literal, plus warning for null

[Timon Gehr]

On 07/03/2013 08:10 PM, bearophile wrote:
> ...
>
> This means you have to keep "null" in the language to represent an empty
> associative array, because someone somewhere will surely want a literal
> that avoids memory allocations. So lot of people will keep using null,
> and the coding situation is improved about zero.
> ...

It would be improved.

Excerpt from my code:

private static Variant[VarDecl] parseContext(void[] mem,FunctionDef fd){
     // ...
     Variant[VarDecl] r;
     // (stupid built-in AAs)
     assert(fd !is null);
     r[cast(VarDecl)cast(void*)fd]=Variant(null);
     r.remove(cast(VarDecl)cast(void*)fd);
     // ...
}

That code using an allocating [:] literal:

private static Variant[VarDecl] parseContext(void[] mem, FunctionDef fd){
     // ...
     Variant[VarDecl] r = [:];
     // ...
}

Is there currently a better way to initialize AAs?