public static bool AllUnique <T, TKey>(this IEnumerable <T> source, Func <T, TKey> selector, IEqualityComparer <TKey>?comparer = null) { return(source.CountBy(selector, comparer).All(x => x.Value == 1)); }
public static bool AllUnique <T, TKey>(this IEnumerable <T> source, Func <T, TKey> selector, IEqualityComparer <TKey>?comparer = null) { return(source.CountBy(selector, comparer).All(x => x.Value == 1)); }