macro_rules! impl_arena_allocatable_decoder { ([]$args:tt) => { ... }; ([decode $(, $attrs:ident)*] [$name:ident: $ty:ty]) => { ... }; }
macro_rules! impl_arena_allocatable_decoder { ([]$args:tt) => { ... }; ([decode $(, $attrs:ident)*] [$name:ident: $ty:ty]) => { ... }; }