Rust should suggest single quotes when expecting `char`

[SergioB-dev]

Code

fn convert_c_to_str(c: char) -> &str {
    match c {
        "A" => "T",
        "C" => "G",
        "T" => "A",
        "G" => "C",
        _ => c,
    }
}

Current output

error[E0308]: mismatched types
 --> src/main.rs:4:9
  |
3 |     match c {
  |           - this expression has type `char`
4 |         "A" => "T",
  |         ^^^ expected `char`, found `&str`

error[E0308]: mismatched types
 --> src/main.rs:5:9
  |
3 |     match c {
  |           - this expression has type `char`
4 |         "A" => "T",
5 |         "C" => "G",
  |         ^^^ expected `char`, found `&str`

error[E0308]: mismatched types
 --> src/main.rs:6:9
  |
3 |     match c {
  |           - this expression has type `char`
...
6 |         "T" => "A",
  |         ^^^ expected `char`, found `&str`

error[E0308]: mismatched types
 --> src/main.rs:7:9
  |
3 |     match c {
  |           - this expression has type `char`
...

Desired output

...

"Please use single quotes ('_') to generate chars"

Rationale and extra context

For beginners the error message could be a lot simpler. Sometimes they just want to make a char and using single quotes instead of double quotes is not terribly obvious.

Other cases

No response

Anything else?

No response

[clubby789]

and as far as I know, all "mainstream" languages use a single quote to denote a character

Both JavaScript and Python have no character type, with " and ' being roughly interchangeable, so this is likely to be a common mistake for newcomers from other languages. Either way, whether it's a typo or a misunderstanding, having an IDE-applicable suggestion will help.