> The closure of the enum is also defined No it's not, you can write totally heterogeneous types in a single const block, as well as intermix iotas and literal

> The closure of the enum is also defined No it's not, you can write totally heterogeneous types in a single const block, as well as intermix iotas and literals. iota may count the same sequence spread across multiple types. There's not even a guarantee that the type definition and the const block exist in the same TU! > There is no other intended purpose. It is often used to generate private context keys, for example.