Suggest adding `&` when a lifetime immediately precedes a type in a generic arg list

[meithecatte]

If one types

fn foo(bar: 'static SomeStruct) { ... }

the compiler could suggest adding a & before the lifetime. This can be more useful in a generic parameter, where a high concentration of special characters makes it easy to not notice the mistake:

fn foo(bar: &mut HashSet<'static SomeStruct>) { ... }

Currently, the error message is just expected one of `,` or `>`, found `SomeStruct` .

[fmease]

I didn't know about this issue but I fixed it in PR #139854 a year ago.

The compiler output now looks like this for your snippet:

error: expected type, found lifetime
 --> src/lib.rs:1:13
  |
1 | fn foo(bar: 'static SomeStruct) {}
  |             ^^^^^^^ expected type
  |
help: you might have meant to write a reference type here
  |
1 | fn foo(bar: &'static SomeStruct) {}
  |             +

[fmease]

Ah but your 2nd example has not been addressed.