Heads-up: UB due to misuse of mem::uninitialized will soon lead to panic

[RalfJung]

Here, this crate causes UB by "Producing an invalid value". Concretely, it creates an arbitrary T with mem::uninitialized(). In the near future the call to mem::uninitialized() will panic to avoid UB, and our crater run determined that this crate will be affected.

mem::uninitialized() is deprecated since Rust 1.39. The intended replacement is MaybeUninit, which tracks the possibility of uninitialized values at the type level to make sure the compiler does not make any false assumptions.

[calixteman]

@RalfJung, any chance to have a fix here ?

[RalfJung]

I'm not familiar with this library I am afraid. I am working on rustc and the library just showed up when we did our regression testing for this change. Cc rust-lang/rust#66151

The library does not seem maintained any more; I am not sure what would be good replacements.

[emilk]

@ilaril made a beautiful fix, and I have released a 1.0.1