Historical language survey

[Walter Bright]

Sean Kelly wrote:
> Walter Bright wrote:
>>
>> And I still don't know anything about M3 <g>. But being able to extend 
>> imports without breaking users can easily be done with some variation 
>> on the PIMPL technique or interfaces.
> 
> But PIMPL only works if combined with header files, and it shouldn't be 
> necessary to resort to this just to avoid symbol collisions with 
> implementation-level stuff.  I do think it's a useful tool when complete 
> implementation hiding is necessary for business reasons, but not as a 
> general tool to work around what feels like a language issue.

It isn't to avoid symbol collisions, it's to make the user of the class 
immune to adding new members to the implementation of the class.