Sorry if the post reads like “rust did this right”: my intention was to show different trade offs around static/dynamic checking of constructors. I didn’t mean

Sorry if the post reads like “rust did this right”: my intention was to show different trade offs around static/dynamic checking of constructors. I didn’t mean to argue that certain approaches are right, and others are wrong. In particular, the section about Swift shows that you can fully statically checked constructors if you dedicate enough language machinery to it. I don’t know a lot about Pony, but it seems like it uses a strict subset of Swift’s rules? There’s no inheritance so two phased initialization is condensed to “don’t call methods until all fields set”. It’s also not possible to call one constructor from another, so designated/convenience constructor split is also absent.