I agrée with them and with you. It looks like they work in some poor language that doesn’t allow overloading. Their example of `frobnicate`ing an optional being bad made me think: why not both? `void frobnicate(Foo&); void frobnicate(std::optional<Foo>& foo) { if (foo.has_value()) { frobnicate(foo); } }`. Now you can frobnicate `Foo`s and optional ones!
Push ifs down:
Polymorphize your fors: