DIP in making: ProtoObject

[Steven Schveighoffer]

On 4/4/18 1:32 AM, Jonathan M Davis wrote:
> On Wednesday, April 04, 2018 00:49:10 Andrei Alexandrescu via Digitalmars-d
> wrote:
>> I'm working on a simple older idea to get it out of the way in
>> preparation for the more difficult DIPs to come:
>>
>> https://github.com/andralex/DIPs/blob/ProtoObject/DIPs/DIPxxxx.md
>>
>> This is not officially reviewable yet, but conveys the gist and could
>> use some early feedback. Any insight will be appreciated.
> 
> Two things I can think of after quickly going over it:
> 
> 1. While issues with attributes and Object are discussed, the fact that
> Object.opEquals requires casting away const and effectively puts a hole in
> the type system is not mentioned. I don't know that it's all that critical
> to mention it given all of the other issues, but it certainly affects how
> overloading opEquals is going to need to be implemented for ProtoObject.
> Presumably, the free function version of opEquals will need to be templated
> with an overload that takes classes which are not derived from Object,
> allowing opEquals to use whatever attributes are appropriate.

Yes, and at some point, we should deprecate the casting version, meaning 
your Object that doesn't define a const opEquals will stop compiling.

> 
> 2. What happens if you put synchronized on a member function when the class
> is not derived from ProtoObjectWithMonitor? I would assume that it would be
> an error, but the DIP doesn't say.

Error. No place to allocate the monitor.

-Steve