Store mutable indirections in immutable data with this one weird trick!

[Imperatorn]

On Saturday, 13 November 2021 at 14:43:00 UTC, Paul Backus wrote:
> On Saturday, 13 November 2021 at 14:35:36 UTC, Imperatorn wrote:
>> On Saturday, 13 November 2021 at 14:32:15 UTC, Paul Backus 
>> wrote:
>>> On Saturday, 13 November 2021 at 13:11:05 UTC, Timon Gehr 
>>> wrote:
>>>> [...]
>>>
>>> In a language where valid programs cannot distinguish between 
>>> different pointers to the same value, or observe the side 
>>> effects of memory allocation, it is natural to define `pure` 
>>> such that it allows memory allocation.
>>>
>>> [...]
>>
>> Many use the "compromise edition" to pure, I think it's ok. 
>> Pure in that sense is just same out for a given in, doesn't 
>> matter what the function does inside.
>
> [`pureMalloc`][1] does not return the same output for a given 
> input.
>
> [1]: https://druntime.dpldocs.info/core.memory.pureMalloc.html

Yeah, these words are not precise enough.