capture a yielded value

capture_yield.rb

class MyClass
  def initialize
    @thevalue = 42
  end

  def omg
    yield @thevalue
  end
end

myobj = MyClass.new

thevalue = catch(:thevalue) do
  myobj.omg { |thevalue|
    throw :thevalue, thevalue
    thevalue * 2
  }
end

p thevalue # => 42