enable

Activates the trace

Return true if trace was enabled. Return false if trace was disabled.

trace.enabled?  #=> false
trace.enable    #=> false (previous state)
                #   trace is enabled
trace.enabled?  #=> true
trace.enable    #=> true (previous state)
                #   trace is still enabled

If a block is given, the trace will only be enabled within the scope of the block.

trace.enabled?
#=> false

trace.enable do
    trace.enabled?
    # only enabled for this block
end

trace.enabled?
#=> false

Note: You cannot access event hooks within the block.

trace.enable { p tp.lineno }
#=> RuntimeError: access from outside