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module Ref
# A WeakReference represents a reference to an object that is not seen by
# the tracing phase of the garbage collector. This allows the referenced
# object to be garbage collected as if nothing is referring to it.
#
# === Example usage:
#
# foo = Object.new
# ref = Ref::WeakReference.new(foo)
# ref.object # should be foo
# ObjectSpace.garbage_collect
# ref.object # should be nil
class WeakReference < Reference
# Create a weak reference to an object.
def initialize(obj)
raise NotImplementedError.new("This is an abstract class; you must require an implementation")
end
# Get the referenced object. If the object has been reclaimed by the
# garbage collector, then this will return nil.
def object
raise NotImplementedError.new("This is an abstract class; you must require an implementation")
end
end
end
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