void main () { variance([1.0, 2, 3]); } alias meanType(T) = T; template variance(bool stable = true) { void variance(Range)(Range r, bool isPopulation = false) { .variance!(double, stable)(r, isPopulation); } } template variance(F, bool stable = true) { void variance(Range)(Range r, bool isPopulation = false) {} void variance(scope const F[] ar...) {} }