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    use proc_macro2::{Ident, TokenStream};
    use quote::format_ident;

    use syn;
    use try;

    pub fn wrap_in_const(
        serde_path: Option<&syn::Path>,
        trait_: &str,
        ty: &Ident,
        code: TokenStream,
    ) -> TokenStream {
        let try_replacement = try::replacement();

        let dummy_const = if cfg!(no_underscore_consts) {
            format_ident!("_IMPL_{}_FOR_{}", trait_, unraw(ty))
        } else {
            format_ident!("_")
        };

        let use_serde = match serde_path {
            Some(path) => quote! {
                use #path as _serde;
            },
            None => quote! {
                #[allow(unused_extern_crates, clippy::useless_attribute)]
                extern crate serde as _serde;
            },
        };

        quote! {
            #[doc(hidden)]
            #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
            const #dummy_const: () = {
                #use_serde
                #try_replacement
                #code
            };
        }
    }

    #[allow(deprecated)]
    fn unraw(ident: &Ident) -> String {
        // str::trim_start_matches was added in 1.30, trim_left_matches deprecated
        // in 1.33. We currently support rustc back to 1.15 so we need to continue
        // to use the deprecated one.
        ident.to_string().trim_left_matches("r#").to_owned()
    }