error[E0308]: mismatched types
  --> $DIR/issue-52893.rs:53:22
   |
LL | impl<F, Name, P> AddClass<Name, F> for Class<P>
   |      - this type parameter
...
LL |         builder.push(output);
   |                 ---- ^^^^^^ expected type parameter `F`, found `Class<P>`
   |                 |
   |                 arguments to this method are incorrect
   |
   = note: expected type parameter `F`
                      found struct `Class<P>`
help: the return type of this call is `Class<P>` due to the type of the argument passed
  --> $DIR/issue-52893.rs:53:9
   |
LL |         builder.push(output);
   |         ^^^^^^^^^^^^^------^
   |                      |
   |                      this argument influences the return type of `push`
note: associated function defined here
  --> $DIR/issue-52893.rs:11:8
   |
LL |     fn push(self, other: T) -> Self::PushRes;
   |        ^^^^

error: aborting due to previous error

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