error[E0425]: cannot find value `y` in this scope
  --> $DIR/mismatched_generic_args.rs:20:9
   |
LL | pub fn add<const U: Dimension>(x: Quantity<f32, U>) -> Quantity<f32, U> {
   |                  - similarly named const parameter `U` defined here
LL |
LL |     x + y
   |         ^ help: a const parameter with a similar name exists: `U`

warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/mismatched_generic_args.rs:1:12
   |
LL | #![feature(generic_const_exprs)]
   |            ^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
   = note: `#[warn(incomplete_features)]` on by default

error: `Dimension` is forbidden as the type of a const generic parameter
  --> $DIR/mismatched_generic_args.rs:11:33
   |
LL | pub struct Quantity<S, const D: Dimension>(S);
   |                                 ^^^^^^^^^
   |
   = note: the only supported types are integers, `bool`, and `char`
help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
   |
LL + #![feature(adt_const_params)]
   |

error[E0107]: trait takes at most 1 generic argument but 2 generic arguments were supplied
  --> $DIR/mismatched_generic_args.rs:14:36
   |
LL | impl<const D: Dimension, LHS, RHS> Add<LHS, D> for Quantity<LHS, { Dimension }> {}
   |                                    ^^^ expected at most 1 generic argument

error: `Dimension` is forbidden as the type of a const generic parameter
  --> $DIR/mismatched_generic_args.rs:14:15
   |
LL | impl<const D: Dimension, LHS, RHS> Add<LHS, D> for Quantity<LHS, { Dimension }> {}
   |               ^^^^^^^^^
   |
   = note: the only supported types are integers, `bool`, and `char`
help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
   |
LL + #![feature(adt_const_params)]
   |

error: `Dimension` is forbidden as the type of a const generic parameter
  --> $DIR/mismatched_generic_args.rs:18:21
   |
LL | pub fn add<const U: Dimension>(x: Quantity<f32, U>) -> Quantity<f32, U> {
   |                     ^^^^^^^^^
   |
   = note: the only supported types are integers, `bool`, and `char`
help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
   |
LL + #![feature(adt_const_params)]
   |

error: aborting due to 5 previous errors; 1 warning emitted

Some errors have detailed explanations: E0107, E0425.
For more information about an error, try `rustc --explain E0107`.