Float-literal mutations: x → x + 1.0, x - 1.0, and 0.0, deduplicated and never equal to x.
The float counterpart of Mutare.Mutators.IntegerLiteral. On by default.
Add project-specific positions to leave alone with the :skip_arguments option (a list of {module, function, arity, positions}, as in Mutare.Mutators.IntegerLiteral).
Filterable variants — qualify a # mutare:ignore filter with :label to suppress just one kind (Mutare.Mutator.variants/0): zero, succ, pred.