deprecated
The decorator @deprecated("Some explanation.") is used in libraries
to deprecate values and often to provide information about what values to use instead.
For example, the List namespace of the standard library has a deprecated function named tail_opt.
Its @deprecated attribute shows what function to use instead:
// @inline
// @deprecated("Use `List.tail` instead.")
const tail_opt = <elt>(list: List.t<elt>) : option<List.t<elt>> =>
List.tail(list);