Macro spectra::impl_load_json_via

macro_rules! impl_load_json_via {
    ($ty_:ty, $intermediate_ty:ty, $desc:expr) => { ... };
}

Implement Load for a type that can be indirectly deserialized from JSON by going from a type that implements JSON deserialization.

This macro will generate the Load instance for $ty_ if $ty_: From<$intermediate_ty> holds.