serde derive codegen v1 from cargo expand

eg.rs

#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
const _IMPL_DESERIALIZE_FOR_Compact: () = {
    extern crate serde as _serde;
    #[automatically_derived]
    impl<'de, T: CompactPart, H: Serialize + for<'de_inner> Deserialize<'de_inner>> _serde::Deserialize<'de>
        for Compact<T, H>
        where T: _serde::Deserialize<'de>
    {
        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
            where __D: _serde::Deserializer<'de>
        {
            let __content =
                match <_serde::private::de::Content as _serde::Deserialize>::deserialize(__deserializer) {
                    ::result::Result::Ok(val) => val,
                    ::result::Result::Err(err) => return ::result::Result::Err(::convert::From::from(err)),
                };
            if let _serde::export::Ok(__ok) =
                       _serde::export::Result::map(<::Compact as
                                                       _serde::Deserialize>::deserialize(_serde::private::de::ContentRefDeserializer::<__D::Error>::new(&__content)),
                                                   Compact::Encoded) {
                    return _serde::export::Ok(__ok);
                }
            _serde::export::Err(_serde::de::Error::custom("data did not match any variant of untagged enum Compact"))
        }
    }
};
#[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
const _IMPL_SERIALIZE_FOR_Compact: () = {
    extern crate serde as _serde;
    #[automatically_derived]
    impl<T: CompactPart, H: Serialize + for<'de_inner> Deserialize<'de_inner>> _serde::Serialize for Compact<T, H>
        where T: _serde::Serialize,
              H: _serde::Serialize
    {
        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
            where __S: _serde::Serializer
        {
            match *self {
                Compact::Decoded { .. } => _serde::export::Err(_serde::ser::Error::custom("the enum variant Compact::Decoded cannot be serialized")),
                Compact::Encoded(ref __field0) => _serde::Serialize::serialize(__field0, __serializer),
            }
        }
    }
};