cudarc's safe driver API has two traits, DeviceRepr and ValidAsZeroBits, which mark types which can be reliably memcopied to the GPU and those which are valid as zeros. Because of the orphan rule they cannot be defined for third-party crates, though.

There are, however, two popular crates: bytemuck and zerocopy, which define similar traits:

• bytemuck has Zeroable and AnyBitPattern, which is a subset of DeviceRepr (it's bidirectional, so it doesn't support types with niches).
• zerocopy has IntoBytes and FromZeros.

And many third-party crates like uuid and half have options to enable implementation for those features. I think it'd be convenient if cudarc had a zerocopy and/or bytemuck features, which would add a blanket implementation of cudarc's traits, i.e.:

// SAFETY: upheld by `Zeroable`'s invariant
unsafe impl<T> ValidAsZeroBits for T where T: zerocopy::Zeroable {}

This would make it easier to interface with third-party crates without the need to resort to a newtype wrapper. The downside is that it adds dependencies and could cause implementation conflicts, but I think that keeping it behind an off by default feature would be fine.

P.S.
I've just discovered cudarc this week and it using it has been a delight, so I wanted to say thanks for it!