Simplify error message with removing lifetime and reference information

[tronta]

The following code provides the following error message:

fn main() {
    "jjj".to_de();
}

error[E0599]: no method named `to_de` found for reference `&'static str` in the current scope
 --> src/main.rs:2:11
  |
2 |     "jjj".to_de();
  |           ^^^^^ method not found in `&'static str`

this could be reduced to

error[E0599]: no method named `to_de` found for `str` in the current scope
 --> src/main.rs:2:11
  |
2 |     "jjj".to_de();
  |           ^^^^^ method not found in `str`

as . is automatically dereferencing and the lifetime also does not matter for this error.

[Aaron1011]

If the method is missing, we cannot know what components of the type may or not matter. For example, the user could have typo'd the following hypothetical method:

impl &'static str {
	fn to_df(self) {}
}

[tronta]

Maybe I just don't get what exactly you mean, but what exactly is missing if I just see the error

error[E0599]: no method named `to_de` found for `str` in the current scope
 --> src/main.rs:2:11
  |
2 |     "jjj".to_de();
  |           ^^^^^ method not found in `str`

I personally don't miss &'static

[Aaron1011]

I don't think we should be displaying a 'simplified' version of the actual type of the method receiver, based on where we think the actual method will be defined.

Also, using #![feature(unsized_locals)] allows you to actually have a local variable of type str (see #48055). If we 'simplify' the error message, the user can no longer tell if the local has type str or &'static str.

[tronta]

Ah. So maybe add that this is a type:

error[E0599]: no method named `to_de` found for type `str` in the current scope
 --> src/main.rs:2:11
  |
2 |     "jjj".to_de();
  |           ^^^^^ method not found for type `str`

[tronta]

Ok, so I close it.