public static TSource?FirstOrNull <TSource>(this IReadOnlyList <TSource> source, Func <TSource, bool> predicate)
where TSource : struct
{
switch (source)
{
case TSource[] array:
return(ArrayExtensions.FirstOrNull <TSource>(array, predicate));
default:
return(ReadOnlyList.FirstOrNull <IReadOnlyList <TSource>, IEnumerator <TSource>, TSource>(source, predicate));
}
}