Absence of isAllocator trait

[Paul Backus]

On Monday, 6 September 2021 at 13:24:56 UTC, Basile B. wrote:
> It's because the clients of an allocator should rather 
> statically check for specific traits of an allocator, there are 
> too many possible permutations of capabilities possible, not 
> all can allocate and deallocate, not all can reallocate, and so 
> on.


According to [the documentation][1], there are two required 
properties all allocators must have:

* `uint alignment`
* `void allocate(size_t size)`

So it makes sense to have an `isAllocator` trait that checks for 
those, even if clients are expected to check for other properties 
individually.

[1]: 
https://dlang.org/phobos/std_experimental_allocator_building_blocks.html