Destructors, const structs, and opEquals

[Don]

Michel Fortin wrote:
> On 2010-12-10 17:12:16 -0500, Don <nospam at nospam.com> said:
> 
>> Steven Schveighoffer wrote:
>>> To summarize for those looking for the C++ behavior, the equivalent 
>>> would be:
>>>
>>> void foo(auto ref const Widget)
>>
>> That use of 'auto' is an abomination.
> 
> One problem I'm starting to realize is that we now have so many 
> available qualifiers for function parameters than it's really easy to 
> get lost.
> 
> In D1 it was simple: "in" for regular arguments (the default), 
> "inout"/"ref" for passing arguments by refrence, and "out" for output 
> arguments. They all had clear semantics and not too much overlap.
> 
> In D2, we've lost this simplicity. Add "const/immutable/shared", add 
> "scope", change "in" as an alias for "const scope", give "inout" a 
> totally new meaning, keep "ref" and "out" the same except that now "ref" 
> can be prefixed with "auto" to give it a double meaning...  choosing the 
> right modifiers for function parameters is getting extra complicated.
> 
> Have we lost track of one of D's principles, that doing the right thing 
> should be the easiest way to do things? To me it looks like we're adding 
> more and more ways to pass arguments because the defaults are failing 
> us. Perhaps it's time to revisit how arguments are passed by default.
> 
> As for "auto ref", if we're to keep it I think it'd be much better if it 
> was a keyword of its own, such as "autoref". Having modifiers is one 
> thing, but having modifiers that apply to modifiers is getting a little 
> hard to parse in my head.

 > This is not unprecedented, in English when one
> qualifier apply to another and it becomes hard to read we group them by 
> adding a hyphen between the two.

The problem is that 'auto' in 'auto ref' has *a contradictory meaning* 
to every other usage of 'auto' in the language.

If we need another keyword, we have to create another keyword.
Almost any other syntax would be better.

And as far as I can tell, 'auto ref', 'scope' and 'in' as function 
parameters aren't explained at all in the spec.