[fpc-pascal] Traits Proposal

[Ryan Joseph]

> On Feb 10, 2021, at 7:47 PM, Martin Frb via fpc-pascal <fpc-pascal at lists.freepascal.org> wrote:
> 
> In that case IIRC, it was said traits are not allowed constructors. Why?

Traits are meant to be a way to import fields/methods and is based off of "object" (so it's on the stack). This is also important for using properties to alias the imported fields. It's the same with subclassing, you don't need to manually allocate the super class because it's all one structure with a shared memory space. The idea is to make a viable alternative to inheritance in the simplest way possible.

> 
>> procedure TMyClass.DoThis;
>> begin
>>   // resolve the conflict by directly referencing the trait
>>   traitA.DoThis;
>> end;
>> 
>> 
> This we already can do. Write our own forwarder method.
> I understand it is for conflict resolution only. But see my example => as soon as you need to repeat a trait with just a change in name, you always need conflict resolution.
> IMHO, there are many traits that a class could need more than once.

I know it's not the most elegant but we need to keep this simple if there's going to be any chance of it even being considered. I will let the compiler team defer to this.

Regards,
	Ryan Joseph