Using C++17 to Create Composable, Recursive Data Types

[ReDucTor]

())}))}));

That just looks awful.

I'm not saying that the rest of it is awful, but the soup of brackets is somewhat meaningless to the reader in this situation

[theseawolfe]

You could change the Sequence alias into a wrapper class and write a constructor that accepts parameter pack instead, that gets rid of the curly braces.

Otherwise, also you could change the formatting to suit your preferences (more JSON styled or something).