in gazebo_derive/src/default.rs [62:70]
fn default_impl(data: &Data) -> TokenStream {
match data {
Data::Struct(data) => default_struct(data),
Data::Enum(x) => syn::Error::new_spanned(x.enum_token, "Can't derive Default for enums")
.into_compile_error(),
Data::Union(x) => syn::Error::new_spanned(x.union_token, "Can't derive Default for unions")
.into_compile_error(),
}
}