Re: Large writable variables

Andres Freund <andres@anarazel.de> writes:
> On 2018-10-16 12:41:44 -0400, Robert Haas wrote:
>> In terms of a function that returns both const and non-const
>> variables, it seems a bit sketchy that the caller would know what the
>> function is doing in particular cases and make decisions based on it,
>> but maybe that's just how life is.

> I don't think it's necessary the callers doing so in most cases. E.g. in
> the DestReceiver case, it'll be the choice of the testreceiver (say
> intorel_receive modifying things for DestIntoRel), not the caller
> choosing when to modify things.  The caller / users of dest receivers
> won't necessarily know.

Yeah, I think the use-case is more like "this API specifies non-const
pointers, but some instances can return pointers to const objects,
while others return non-const objects".  Changing the API to const
isn't better, it just moves where you have to cast away const.

            regards, tom lane