AsyncRead: read with a library-provided buffer

[nrc]

To use io_uring's buffer pools, I think we need a method of reading which lets the library manage a buffer pool and reading to return a buffer without the caller providing one. I'm not sure what the work flow between concrete and abstract types looks like here, or what exactly should be returned (&[u8]? OwnedBuf? An associated type?).

[NobodyXu]

What about an erased type contains a v-table?

I don't think it can return &[u8] since the io-uring managed buffer pool cannot have lifetime &'static and it also needs a Drop::drop impl to recycle the buffer.

[Noah-Kennedy]

This has been the direction I've been thinking about as well.