Attribute Macro impl_fn_decoration

#[impl_fn_decoration]
Expand description

Internal macro for dealing with function decorations (#[decreases(...)], #[ensures(...)], #[requires(...)]) on fn items within an impl block. There is special handling since such functions might have a self argument: in such cases, we rewrite function decorations as #[impl_fn_decoration(<KIND>, <GENERICS>, <WHERE CLAUSE>, <SELF TYPE>, <BODY>)].