[Test]

[ExpectedException(typeof(InvalidOperationException))]

public void ExpectAnExceptionByType()

{

/* … */

}

A attribute can do the same. This is NUnit’s but you can write your own. Not as nice but the logic is kept in one method as you require.

public IEnumerator traverse()

{

left.traverse();

yield this;

right.traverse();

}

Even easier, I think.

using (Stream file = File.OpenRead("foo.txt"))

{

// do stuff with file

}

Exactly the same and more efficient since no method invocation is made.

Off course, this aren’t true closures but other features of C# that allow the same things you are (ab?)using closures for on Ruby.

Ciao…