error: equality constraints are not yet supported in `where` clauses
  --> $DIR/missing-bounds.rs:37:33
   |
LL | impl<B: Add> Add for E<B> where <B as Add>::Output = B {
   |                                 ^^^^^^^^^^^^^^^^^^^^^^ not supported
   |
   = note: see issue #20041 <https://github.com/rust-lang/rust/issues/20041> for more information
help: if `Output` is an associated type you're trying to set, use the associated type binding syntax
   |
LL | impl<B: Add> Add for E<B> where B: Add<Output = B> {
   |                                 ~~~~~~~~~~~~~~~~~~

error[E0308]: mismatched types
  --> $DIR/missing-bounds.rs:11:11
   |
LL | impl<B> Add for A<B> where B: Add {
   |      - this type parameter
...
LL |         A(self.0 + rhs.0)
   |           ^^^^^^^^^^^^^^ expected type parameter `B`, found associated type
   |
   = note: expected type parameter `B`
             found associated type `<B as Add>::Output`
help: consider further restricting this bound
   |
LL | impl<B> Add for A<B> where B: Add + Add<Output = B> {
   |                                   +++++++++++++++++

error[E0308]: mismatched types
  --> $DIR/missing-bounds.rs:21:14
   |
LL | impl<B: Add> Add for C<B> {
   |      - this type parameter
...
LL |         Self(self.0 + rhs.0)
   |              ^^^^^^^^^^^^^^ expected type parameter `B`, found associated type
   |
   = note: expected type parameter `B`
             found associated type `<B as Add>::Output`
help: consider further restricting this bound
   |
LL | impl<B: Add + Add<Output = B>> Add for C<B> {
   |             +++++++++++++++++

error[E0369]: cannot add `B` to `B`
  --> $DIR/missing-bounds.rs:31:21
   |
LL |         Self(self.0 + rhs.0)
   |              ------ ^ ----- B
   |              |
   |              B
   |
help: consider restricting type parameter `B`
   |
LL | impl<B: std::ops::Add<Output = B>> Add for D<B> {
   |       +++++++++++++++++++++++++++

error[E0308]: mismatched types
  --> $DIR/missing-bounds.rs:42:14
   |
LL | impl<B: Add> Add for E<B> where <B as Add>::Output = B {
   |      - this type parameter
...
LL |         Self(self.0 + rhs.0)
   |              ^^^^^^^^^^^^^^ expected type parameter `B`, found associated type
   |
   = note: expected type parameter `B`
             found associated type `<B as Add>::Output`
help: consider further restricting type parameter `B`
   |
LL | impl<B: Add> Add for E<B> where <B as Add>::Output = B, B: Add<Output = B> {
   |                                                       ++++++++++++++++++++

error: aborting due to 5 previous errors

Some errors have detailed explanations: E0308, E0369.
For more information about an error, try `rustc --explain E0308`.