macro_rules! for_all_global_param_keys { ($f:ident::<Key>($($args:expr),*);) => { ... }; ($f:ident::<Key>($($args:expr),*)?;) => { ... }; }
macro_rules! for_all_global_param_keys { ($f:ident::<Key>($($args:expr),*);) => { ... }; ($f:ident::<Key>($($args:expr),*)?;) => { ... }; }