proc_macro main wrapper

gistfile1.rs

#[proc_macro_attribute]
pub fn main(_attr: TokenStream, item: TokenStream) -> TokenStream {
    let input = parse_macro_input!(item as ItemFn);

    let fn_name = &input.sig.ident; // Function name

    if fn_name != "main" {
        panic!("[macro name] can be derived only on main function!");
    }

    let fn_output = &input.sig.output; // Function output
    let scope = input.block;

    quote! {
        fn #fn_name() #fn_output {
            #scope
        }
    }
    .into()
}