Is there a reason for the absence of an isAllocator trait under std.experimental.allocator?

On Saturday, 4 September 2021 at 19:43:27 UTC, Per Nordlöw wrote:

I had ask a similar Q once and I've been told that (more or less):

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.

actually I'm 100% sure that what you want is isMallocator and not isAllocator ;)

On Monday, 6 September 2021 at 13:24:56 UTC, Basile B. wrote:

According to the documentation, 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.

On Monday, 6 September 2021 at 15:46:52 UTC, Paul Backus wrote:

Should be

• void[] allocate(size_t size)

Thanks. Here's what I have so far

enum isAllocator(T) = (is(typeof(T.allocate(size_t.init)) == void[]) &&
                       is(typeof(T.alignment) == uint));