Can we just have struct inheritence already?

[Timon Gehr]

On 13.06.19 23:45, Walter Bright wrote:
> On 6/13/2019 12:51 PM, Timon Gehr wrote:
>> On 13.06.19 21:44, Walter Bright wrote:
>>> On 6/13/2019 4:30 AM, Timon Gehr wrote:
>>>> Yes. IMHO this shouldn't be a @safe pure operation.
>>>
>>> D regards converting a pointer to an int as safe, but not the other 
>>> way around.
>>
>> I know, and that is fine, but casting a pointer to int is not pure. It 
>> glances into the global state maintained by the memory allocator.
> 
> We had a discussion a while back about whether allocating memory via new 
> was pure or not, since a different value was produced each time. We 
> eventually took the pragmatic route that pure functions would be next to 
> useless if this was not allowed.

It is obvious that allocation has to be pure. However, accessing the 
address of your data is impure. The runtime systems of pure functional 
languages also allocate memory, but the addresses are not exposed to the 
pure user code.