As it happens Math::Round offers the nearest(UNITS, NUM) function that does exactly this. As the snap_basic() function is legacy dross and significant figures are handled by Math::SigFigs I have decided to delete this module as it does not offer anything not already available. This is a pity as I really liked the name. See Fix floats like you do in your head for more discussion and rationale.

cheers

tachyon

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