Discussion Thread: DIP 1042--ProtoObject--Community Review Round 1

[Timon Gehr]

On 15.01.22 11:22, Elronnd wrote:
> On Saturday, 15 January 2022 at 10:17:39 UTC, Timon Gehr wrote:
>> Seems like that would make class object construction impure.
> 
> Meh paper over it with implementation-specific hacks.

You can't, as any `pure` function can just call toHash.

> No one complains about pureMalloc.

Not true, but that problem is a bit more nuanced and I think it can be 
fixed.

https://dlang.org/library/core/memory/pure_malloc.html


```
UNIX 98 requires that errno be set to ENOMEM upon failure. Purity is 
achieved by saving and restoring the value of errno, thus behaving as if 
it were never changed.
```

Of course, never mind that it will return `null` upon failure. Some sort 
of special casing of out-of-memory conditions seems inevitable (by the 
GC, it's treated as an unrecoverable error, probably pureMalloc should 
throw an OutOfMemoryError too in this case).

> (Well, arguably people _should_ be complaining about 
> pureFree--pureMalloc is fine though--but.)

At least pureFree is not @safe. Of course, there is the whole issue that 
its signature looks exactly like something that can often just be 
optimized away. x)