error[E0308]: mismatched types
  --> $DIR/different-fn.rs:10:5
   |
LL |     [0; size_of::<Foo<T>>()]
   |     ^^^^^^^^^^^^^^^^^^^^^^^^ expected `size_of::<T>()`, found `0`
   |
   = note: expected constant `size_of::<T>()`
              found constant `0`

error: unconstrained generic constant
  --> $DIR/different-fn.rs:10:9
   |
LL |     [0; size_of::<Foo<T>>()]
   |         ^^^^^^^^^^^^^^^^^^^
   |
help: try adding a `where` bound
   |
LL | fn test<T>() -> [u8; size_of::<T>()] where [(); size_of::<Foo<T>>()]: {
   |                                      ++++++++++++++++++++++++++++++++

error: aborting due to 2 previous errors

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