error[E0277]: the size for values of type `<Self as std::ops::Deref>::Target` cannot be known at compilation time
  --> $DIR/issue-42312.rs:4:29
   |
LL |     fn baz(_: Self::Target) where Self: Deref {}
   |                             ^ doesn't have a size known at compile-time
   |
   = help: the trait `std::marker::Sized` is not implemented for `<Self as std::ops::Deref>::Target`
   = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
   = help: consider adding a `where <Self as std::ops::Deref>::Target: std::marker::Sized` bound
   = note: all function arguments must have a statically known size
   = help: unsized locals are gated as an unstable feature

error[E0277]: the size for values of type `(dyn std::string::ToString + 'static)` cannot be known at compilation time
  --> $DIR/issue-42312.rs:8:23
   |
LL | pub fn f(_: ToString) {}
   |                       ^ doesn't have a size known at compile-time
   |
   = help: the trait `std::marker::Sized` is not implemented for `(dyn std::string::ToString + 'static)`
   = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
   = note: all function arguments must have a statically known size
   = help: unsized locals are gated as an unstable feature

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.