zerocopy wanted features & bugfixes #1239

Note: see as well:

• Tracking Issue: Rust for Linux google/zerocopy#3348.

Features that we would like to see

Required (we almost certainly want them)

Nice to have (not critical, we could workaround if needed, etc.)

• Remove duplicated example in IntoBytes::write_to_suffix.

  • PR: Remove duplicated example in IntoBytes::write_to_suffix google/zerocopy#3422.

• transmute!: Support generic types by deferring size equality check to PME.

  • Lore: https://lore.kernel.org/rust-for-linux/20260901-typed_register-v4-2-5552b1d59525@garyguo.net/.
  • Issue: transmute!: Support generic types by deferring size equality check to PME google/zerocopy#3610.
  • Rust Tracking Issue (next-gen transmute, transmute_neo, union_transmute): Experimental Tracking Issue for Next-Gen Transmute rust-lang/rust#155079.

Low priority (we will likely not use them in the end)

Done (stabilized, fixed, not needed anymore, etc.)

• cfg(no_fp_fmt_parse).

  • Issue: Linux kernel: cfg(no_fp_fmt_parse) google/zerocopy#3426.
  • PR: [byteorder] Add cfg no_fp_fmt_parse google/zerocopy#3429 (v0.8.51).

• Supporting non_ascii_idents.

  • Issue: Linux kernel: supporting non_ascii_idents google/zerocopy#3427.
  • PR (Rust): rustc_lint: Allow scoped non_ascii_idents lint levels rust-lang/rust#157497.
    • On the kernel side, we will need to work around it until we bump the MSRV, thus likely late 2027, since we follow Debian Stable.
  • Zulip: https://rust-lang.zulipchat.com/#narrow/channel/213817-t-lang/topic/Macros.20and.20getting.20a.20fresh.20identifier/near/600143928.

• "Silent-on-error" derives (under --cfg zerocopy_unstable_linux).

  • Zulip: https://rust-for-linux.zulipchat.com/#narrow/channel/605308-zerocopy/topic/Silent.20derives.20and.20.60feature.28trivial_bounds.29.60/near/599229793.
  • PR (older one, related): [derive] Implement #[zerocopy(on_error = skip/fail)] google/zerocopy#2982.
  • PR: Introduce derive(most_traits) and rename unstable linux cfg google/zerocopy#3416 (v0.8.52).

• SPDX license identifiers.

  • Issue: Linux kernel: SPDX license identifiers google/zerocopy#3428.
  • PR: zerocopy: add SPDX-License-Identifier to source files google/zerocopy#3432.
  • PR: zerocopy: add SPDX-License-Identifier to source files google/zerocopy#3455 (v0.8.52).

• SPDX license identifier for style.css.

  • Issue: Linux kernel: SPDX license identifiers for style.css google/zerocopy#3457.
  • PR: Add SPDX license identifier to rustdoc/style.css google/zerocopy#3458 (v0.8.53).

• Inline functions so that zerocopy doesn't export symbols.

  • Lore: https://lore.kernel.org/rust-for-linux/DJT5P43GJ9MT.2527G7CFCEW46@garyguo.net/.
  • PR: Add unconditional #[inline] to layout helper functions google/zerocopy#3483 (v0.8.54).

Bugs that we would like to see fixed

Required (we almost certainly want them)

Nice to have (probably not critical, we could workaround if needed, etc.)

Low priority (we will likely not use them in the end)

Done (stabilized, fixed, or not needed anymore, etc.)

• most_traits is rendered by default in zerocopy-derive.
  • Issue: most_traits is documented by default google/zerocopy#3466.
  • PR: Hide unstable derive(most_traits) in documentation google/zerocopy#3470 (v0.8.53).