Collections question

[Luís Marques via Digitalmars-d]

On Friday, 27 November 2015 at 20:14:21 UTC, Andrei Alexandrescu 
wrote:
> There's this oddity of built-in hash tables: a reference to a 
> non-empty hash table can be copied and then both references 
> refer to the same hash table object. However, if the hash table 
> is null, copying the reference won't track the same object 
> later on.

I keep hoping that that design decision would be changed...

> 1. Factory function:

Something I find deeply unsatisfying about D structs is their 
inability to reliably set non-trivial invariants, due to the lack 
of custom default ctors. If you are careful, you @disable this(), 
and provide a factory function that sets the invariant. But then, 
you aren't doing much more than renaming this() to make() or 
whatever. The issues with .init could be addressed without 
prohibiting a default ctor...