using System; using System.Collections; namespace NUnit.Framework.Constraints { public class NoItemConstraint : PrefixConstraint { public NoItemConstraint(IConstraint itemConstraint) : base(itemConstraint) { base.DisplayName = "None"; descriptionPrefix = "no item"; } public override ConstraintResult ApplyTo<TActual>(TActual actual) { if (!(((object)actual) is IEnumerable)) throw new ArgumentException("The actual value must be an IEnumerable", "actual"); foreach (object item in (IEnumerable)(object)actual) { if (baseConstraint.ApplyTo(item).IsSuccess) return new ConstraintResult(this, actual, ConstraintStatus.Failure); } return new ConstraintResult(this, actual, ConstraintStatus.Success); } } }