One could also think of it as an algebra of structs.

It would be nice to be able to do stuff like

A + B, A - B(possibly useless), A*B(possibly useless), etc...

A + B would just combine the members, A - B could remove the members that overlap, A*B could qualify overlapping members.

Usually, given types A and B, A+B means `A or B` (in D, std.typecons.Algebraic!(A,B) ) and A*B means the tuple containing A and B (in D, std.typecons.Tuple!(A,B) ).

What you're trying to do is doable in D, but you'd have to define it a bit more:

if we have

struct A { int a; int b}

struct B { int b; int a} // just a and b swapped.

What is `A+B`? `A-B`?