Check if an array has same elements than other, regardless of the order

I'm not sure if its a Rspec question, but I only encountred this problem on Rspec tests.

I want to check if an array is equal to another array, regardless of the elements order :

[:b, :a, :c] =?= [:a, :b, :c]

My current version :

my_array.length.should == 3
my_array.should include(:a)
my_array.should include(:b)
my_array.should include(:c)

Is there any method on Rspec, ruby or Rails for do something like this :

my_array.should have_same_elements_than([:a, :b, :c])