Copy Constructor DIP

[Andrei Alexandrescu]

On 07/12/2018 02:54 AM, RazvanN wrote:
>> What's wrong with:
>> struct S {
>>   this(ref S copyFrom);
>> }
>>
>> That looks like a perfectly good copy constructor declaration ;) I'm 
>> just saying, the DIP needs to explain this.
> 
> That is actually a valid constructor, according to today's compiler. There
> might be code out there that uses this syntax for the constructor and 
> overnight
> it will be turned into a copy constructor.
> 
> I agree that the current syntax is lacking. This was Andrei's proposition
> and I was initially against it, but he said to put it in the DIP so that
> we can discuss it as a community. Maybe this syntax is better:
> 
> @this(ref S a another)
> 
> It looks like the c++ copy constructor but the `@` makes it different from
> a constructor, so we're good. What do you think?

We will not add syntax if we can help it.