Macro spirt::spv::spec::raw::dew_and_then

macro_rules! dew_and_then {
    ($($name:ident: |$x:ident: $in_ty:ty| -> $out_ty:ty $body:block),* $(,)?) => { ... };
}

Helper to generate functions usable with deserialize_with (hence “dew”), that deserialize to an intermediary type, which is then passed through the supplied closure, which is allowed to error. This is similar to the serde attribute #[serde(try_from = "...")], but that only works for whole types.