[unhammer]

https://programmers.stackexchange.com/questions/231092/is-pa... points out some differences.

Some of the things that make me miss OCaml variants/sum types when I have to use C++ subclassing/dynamic dispatch instead: * very lightweight syntax both for creating them and matching on them (and lightweight representation; variants without arguments are just ints under the hood) * compile-time checks on exhaustiveness in pattern matches (so no unexpected NULL's!)

Note that OCaml also allows open/polymorphic variants for the cases where you want to allow expanding the list of options – here the compiler will only check that e.g. a function that matches on only `A|`B won't be sent a `C, although it can be sent a member of a type that contains only `A's. This is typically used for public interfaces where you want to let your implementation expand later (e.g. your current function accepts `UTF8|`UTF16 but you might later decide to accept `WTF8 as well).