Fix build

[Avi-D-coder]

On a different note is there anything fundamental preventing a non accelerated version from compiling on stable?

[mtak-]

Sorry for the delay in review. I'm gonna spend some time today getting the new htm intrinsics working and merged, and then review this.

On a different note is there anything fundamental preventing a non accelerated version from compiling on stable?

The main issue preventing swym from being on stable is described here.

The tl;dr is that swym uses a Borrow by memcpy type of approach to avoid allocations and extra indirections (borrow returns a snapshot of the memory). This is not safe for types containing an UnsafeCell. TCell<T>::borrow requires T: Freeze (named Borrow in this library) to prevent that. Freeze cannot be written in stable rust because it requires optin_builtin_traits.

There are alternative ways of implementing borrow, but they either add overhead or require T: Copy.

[mtak-]

Do you know if there's another way to cfg out the test feature - or if it's even necessary? PR looks great!

[Avi-D-coder]

I don't know a way unfortunately.