Ruby: === operator

@asmallteapot

Recently I was looking at creating a patch for Mocha that would allow you to specify a class as an argument. The feature was added to allow you to specify that an argument can be any instance of the class specified.object.expects(:do_this).with(Fixnum, true, 99) object.do_this(2, true, 99) # satisfies the expectation To support this new feature I looked into the === method. The === method of Object is defined as:Case Equality—For class Object, effectively the same as calling #==, but typically overridden by descendents to provide meaningful semantics in case statements. There's no mystery here, use === like ==. However, the === method of Module provides the behavior I'm looking for.Case Equality—Returns true if anObject is an instance of mod or one of mod‘s descendents. Of limited use for modules, but can be used in case statements to classify objects by class. The documen...

Full article: http://blog.jayfields.com/2007/03/ruby-operator.html?m=1