Type mismatch method suggestion doesn't work for as_deref

[jplatte]

It would be really nice if the mismatched type diagnostic would work for as_deref. Currently, trying to use Option<Vec<String>> where Option<&[String]> is expected doesn't give a method call suggestion the way one gets a suggestion to borrow when trying to use Vec<String> where &[String] is expected.

   = note: expected enum `std::option::Option<&[std::string::String]>`
              found enum `std::option::Option<Vec<std::string::String>>`

^ no suggestion

[jplatte]

Hm actually it also doesn't work for as_ref or cloned / copied. Are there just special cases for some &str / String and Vec / slice method but no general mechanism?

[jplatte]

Fixed by #111659, I think.