这是我的货物

[package]
name = "tmp"
version = "0.1.0"
edition = "2021"

[dependencies]
chrono = "0.4.24"
chrono-tz = {version="0.8.2", optional = true}

[features]
my_feature = ["chrono-tz"]

下面是我的src/main.rs：

#[cfg(feature = "some_feature")]
use chrono_tz::Tz;

#[cfg(feature = "some_feature")]
fn my_fn(tz: Tz){
    println!("tz is: {:?}", tz);
}

fn feature_function(tz: Option<Tz>) {
    match tz {
        #[cfg(feature = "some_feature")]
        Some(tz) => my_fn(tz),
        _ => (),
    }
}

fn main() {
    feature_function(None);
}

请注意feature_function是如何接受tz: Optional<Tz>的，但只有在启用“some_feature”时才会达到Some(tz)的情况。
因此，如果我没有启用“some_feature”，我希望能够用tz=None调用feature_function。
可以预见，这不会编译：

error[E0412]: cannot find type `Tz` in this scope
  --> src/main.rs:10:32
   |
10 | fn feature_function(tz: Option<Tz>) {
   |                                ^^ not found in this scope
   |
help: you might be missing a type parameter
   |
10 | fn feature_function<Tz>(tz: Option<Tz>) {
   |                    ++++

For more information about this error, try `rustc --explain E0412`.
error: could not compile `tmp` due to previous error

有没有一些技巧可以用来在feature_function中输入tz，这样如果没有启用“some_feature”，那么我仍然可以用tz=None调用feature_function？