error[E0308]: mismatched types
  --> $DIR/wf_obligation.rs:17:17
   |
LL |     foo::<_, L>([(); L + 1 + L]);
   |                 ^^^^^^^^^^^^^^^ expected `N + 1 + M`, found `L + 1 + L`
   |
   = note: expected constant `N + 1 + M`
              found constant `L + 1 + L`

error: unconstrained generic constant
  --> $DIR/wf_obligation.rs:17:22
   |
LL |     foo::<_, L>([(); L + 1 + L]);
   |                      ^^^^^^^^^
   |
   = help: try adding a `where` bound using this expression: `where [(); L + 1 + L]:`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0308`.