fix: clippy deny on empty map struct

[paq]

Issue

The FromMessagePack derive macro generates for _ in 0..0 for empty map structs, which clippy denies¹.

Example code

#[derive(ToMessagePack, FromMessagePack, Debug, PartialEq)]
#[msgpack(map)]
struct Empty {}

let empty = Empty {};
let data = zerompk::to_msgpack_vec(&empty).unwrap();

Fix

Added #[allow(clippy::reversed_empty_ranges)] on the generated loop.

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Footnotes

1. https://rust-lang.github.io/rust-clippy/master/index.html#reversed_empty_ranges ↩

[Copilot]

Pull request overview

This PR fixes a Clippy -D warnings failure caused by the FromMessagePack derive macro generating an empty range loop (for _ in 0..0) for map-based structs/variants with zero fields.

Changes:

• Adds #[allow(clippy::reversed_empty_ranges)] to the generated map-deserialization loop for empty map structs.
• Adds the same allow attribute to the generated map-deserialization loop for map-represented enum variants with zero active fields.

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[nuskey8]

Merged the PR. Thanks!