1use proc_macro::TokenStream;
2use quote::quote;
3use syn::{parse_macro_input, DeriveInput};
4
5#[proc_macro_derive(CriticalKey)]
6pub fn derive_critical_key(input: TokenStream) -> TokenStream {
7 let input = parse_macro_input!(input as DeriveInput);
8 let name = &input.ident;
9 let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
10
11 let expanded = quote! {
12 #[automatically_derived]
13 impl #impl_generics CriticalKey for #name #ty_generics #where_clause {
14 fn channel() -> &'static str {
15 concat!(module_path!(), "::", stringify!(#name))
16 }
17 }
18 };
19
20 expanded.into()
21}