Clippy (even more) unhappy about 0.23.x

[domenukk]

Even with 0.23.1, clippy complains when updating TypedBuilder as follows:

error: since `&` implements the `Copy` trait, `&Option<&T>` can be simplified to `Option<&T>`
   --> crates/libafl/src/events/launcher.rs:132:10
    |
132 | #[derive(TypedBuilder)]
    |          ^^^^^^^^^^^^ in this derive macro expansion
    |
   ::: /usr/local/google/home/dmnk/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/typed-builder-macro-0.23.1/src/lib.rs:11:1
    |
 11 | pub fn derive_typed_builder(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
    | -------------------------------------------------------------------------------------- in this expansion of `#[derive(TypedBuilder)]

The code is here:
https://github.com/AFLplusplus/LibAFL/blob/18b4d2d4d522ac6c53900f2045750332e81a504e/crates/libafl/src/events/launcher.rs#L132

I'm running RUSTFLAGS="-Zmacro-backtrace" cargo +nightly clippy --no-deps --tests --examples --benches --all-features on this PR: AFLplusplus/LibAFL#3515

I tried commenting out some of the entries but couldn't find the culprit. If needed I can spend more time on this, but you might know better.

[idanarye]

After bisecting a bit the LibAFL struct, I've managed to find a minimal replication:

#[derive(TypedBuilder)]
struct BigStruct<'a> {
    option_with_ref: Option<&'a str>,

    #[builder(default = None)]
    option_with_default: Option<()>,
}

[idanarye]

@domenukk Can you verify that branch fix/issue-174/clippy-ref_option_ref fixes it for you?

[domenukk]

@domenukk Can you verify that branch fix/issue-174/clippy-ref_option_ref fixes it for you?

Builds without warnings, thank you for the quick fix!