Exactly. The difference here is that std::variant doesn’t “name” the options, you just get the type (and an index, so variant can contain duplicate types). So y

Exactly. The difference here is that std::variant doesn’t “name” the options, you just get the type (and an index, so variant can contain duplicate types). So you have to have some marker type that’s like “this contains nothing”. Fundamentally, Rust’s enums are a much better way of doing this thing compared to std::variant, but C++ did the best it could without changing the core language. Which arguably they should have done.