error[E0369]: cannot add `T` to `Wrapper<T>`
  --> $DIR/restrict-type-not-param.rs:8:7
   |
LL |     a + b
   |     - ^ - T
   |     |
   |     Wrapper<T>
   |
note: an implementation of `Add<_>` might be missing for `Wrapper<T>`
  --> $DIR/restrict-type-not-param.rs:3:1
   |
LL | struct Wrapper<T>(T);
   | ^^^^^^^^^^^^^^^^^ must implement `Add<_>`
note: the trait `Add` must be implemented
  --> $SRC_DIR/core/src/ops/arith.rs:LL:COL
help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
   |
LL | fn qux<T>(a: Wrapper<T>, b: T) -> T where Wrapper<T>: Add<T, Output = T> {
   |                                     ++++++++++++++++++++++++++++++++++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0369`.