Elements.RTL.List.FindIndex(Predicate<T> Match)

When using RTL List.FindIndex(), what value does it return if no match is found in the list? Is it -1? The documentation doesn’t state: https://docs.elementscompiler.com/API/ElementsRTL/Classes/List-T-/

Yes, all of RTL uses -1 for “unavailable index” — be it lists, strings, etc.