callcc()
public
Generates a Continuation object, which it passes to the associated block. You need to require ‘continuation’ before using this method. Performing a cont.call will cause the #callcc to return (as will falling through the end of the block). The value returned by the #callcc is the value of the block, or the value passed to cont.call. See class Continuation for more details. Also see Kernel#throw for an alternative mechanism for unwinding a call stack.