Re: Coercing a `ByteArray#` into a `MutableByteArray#`

Adithya Kumar writes:

Hello all,

I have a use-case where I want to convert `ByteArray#` to `MutableByteArray#` without the copy overhead.

Is the underlying memory structure of `ByteArray#` and `MutableByteArray#` the same?

If I can guarantee that I won't mutate my `MutableByteArray#`, can I use `unsafeCoerce#` on `ByteArray#` and treat it as `MutableByteArray#`?

Note that a future release of GHC (IIRC 9.10) will have a (no-op) operation for precisely this purpose. See [1]. Cheers, - Ben [1] https://gitlab.haskell.org/ghc/ghc/-/issues/22710