There is another way, you can declare option as type Option[T any] *T nil is None opt == nil instead of IsNone() func Some[T any](t T) Option[T]

There is another way, you can declare option as type Option[T any] *T nil is None opt == nil instead of IsNone() func Some[T any](t T) Option[T] { return &t } *opt instead of opt.Get() option.Map(opt, func(x int) double { return double(x) }) for the monadic behavior I wish there was type inference for function arguments, so that you could write func(x) { return double(x) }. Maybe in a couple of years the Go team could be convinced.