C# Enum Flags Extension Methods

Example.cs

namespace MyNamespace
{
	using NUnit.Framework;

	public class Example
	{
		[Test]
		public void Test()
		{
			MyEnum foo = MyEnum.None;
			Assert.IsFalse(MyEnum.All.ContainsAny(foo));

			foo = foo.Add(MyEnum.A);
			Assert.IsTrue(MyEnum.All.ContainsAny(foo));

			foo = foo.Add(MyEnum.B).Remove(MyEnum.A);
			Assert.IsFalse(foo.ContainsAll(MyEnum.AB));
			Assert.IsTrue(foo.ContainsAll(MyEnum.B));

			foo = foo.Toggle(MyEnum.C);
			Assert.IsTrue(foo.ContainsAll(MyEnum.BC));

			foo = foo.Set(MyEnum.A, true);
			Assert.IsTrue(MyEnum.All.ContainsAll(foo));

			foo = foo.Set(MyEnum.AC, false);
			Assert.IsFalse(foo.ContainsAny(MyEnum.A));
			Assert.IsTrue(foo.ContainsAny(MyEnum.B));
			Assert.IsFalse(foo.ContainsAny(MyEnum.C));
		}
	}
}

MyEnum.cs

namespace MyNamespace
{
	[System.Flags]
	public enum MyEnum
	{
		None = 0,
		A = 1 << 0,
		B = 1 << 1,
		C = 1 << 2,
		AB = A | B,
		AC = A | C,
		BC = B | C,
		All = ~None,
	}
}

MyEnumExtensions.cs

namespace MyNamespace
{
	public static class MyEnumExtensions
	{
		public static MyEnum Add(this MyEnum @enum, MyEnum flags)
		{
			return @enum |= flags;
		}

		public static bool ContainsAny(this MyEnum @enum, MyEnum flags)
		{
			return (@enum & flags) > 0;
		}

		public static bool ContainsAll(this MyEnum @enum, MyEnum flags)
		{
			return (@enum & flags) == flags;
		}

		public static MyEnum Remove(this MyEnum @enum, MyEnum flags)
		{
			return @enum &= ~flags;
		}

		public static MyEnum Set(this MyEnum @enum, MyEnum flags, bool isEnabled)
		{
			return isEnabled ? @enum.Add(flags) : @enum.Remove(flags);
		}

		public static MyEnum Toggle(this MyEnum @enum, MyEnum flags)
		{
			return @enum ^= flags;
		}
	}
}