bevy_enhanced_input_macros 0.19.2

Bevy Enhanced Input Macros
Documentation 
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use proc_macro::TokenStream;
use quote::quote;
use syn::{DeriveInput, Error, Path, parse_macro_input};

#[proc_macro_derive(InputAction, attributes(action_output))]
pub fn input_action_derive(item: TokenStream) -> TokenStream {
    let input = parse_macro_input!(item as DeriveInput);

    let Some(attr) = input
        .attrs
        .iter()
        .find(|a| a.path().is_ident("action_output"))
    else {
        return Error::new_spanned(&input, "Missing #[action_output(Type)] attribute")
            .to_compile_error()
            .into();
    };

    let output_ty = match attr.parse_args::<Path>() {
        Ok(output_ty) => output_ty,
        Err(e) => return e.to_compile_error().into(),
    };

    let trait_name = quote! { ::bevy_enhanced_input::prelude::InputAction };
    let struct_name = input.ident;
    let (impl_generics, type_generics, where_clause) = input.generics.split_for_impl();

    TokenStream::from(quote! {
        impl #impl_generics #trait_name for #struct_name #type_generics #where_clause {
            type Output = #output_ty;
        }
    })
}