Add support for impl mode structs to be repr(packed)

[GnomedDev]

This allows the following code to compile, with the only downside being a possible copy of the internal value for non-packed types, although I'm somewhat certain that would be optimised out.

#[repr(packed)]
struct Example(u64);

bitflags::bitflags! {
    impl Example: u64 {
        ...
    }
}

[GnomedDev]

Seems like CI failing is unrelated?

[Nilstrieb]

This should probably have a test to ensure it continues to work.

[GnomedDev]

Seems like there aren't any tests for impl other than the examples, should I add a file for specifically this in src/tests?

[KodrAus]

Hi @GnomedDev 👋

Thanks for the PR. If you add a test to tests/compile-pass called something like bitflags_impl_repr_packed with your example that should make sure we don't regress anything. The current UI failure is unrelated to your changes. If you rebase on main they should start working again.

[GnomedDev]

Hey @KodrAus, just done that!

[KodrAus]

Thanks @GnomedDev! This looks good to me.

[GnomedDev]

Thanks for merging, any chance for a release now with this in? I'm stoked to use it!