Performs a linear scan of buf from $(LP)buf.length .. 0], returning the index of the first element where pred returns true.
The array to search.
The evaluation predicate, which should return true if the element is a valid match and false if not. This predicate may be any callable type.
The index of the first match or buf.length if no match was found.
See Implementation
Performs a linear scan of buf from $(LP)buf.length .. 0], returning the index of the first element where pred returns true.