So take this example here:

'''
proc adder(x: int, y: int): float {.discardable.} =
    var tempValue = float( x + y)
    echo tempValue


adder(7,4)'''

This works because of the {.discardable.}, or I would have to put - echo
adder(7,4).
What you're saying is, if I don't use the actual result of the function (like by
'echo-ing' it), I'll get the error. Is that right?