Improved diagnostics for non-primitive cast on non-primitive types (Arc, Option) by Kivooeo · Pull Request #140196 · rust-lang/rust (original) (raw)
here is a small fix that improving error messaging when user is trying to do something like this
let _ = "x" as Arc; let _ = 2 as Option;
before it looks like this
error[E0605]: non-primitive cast: &'static str as Arc<str>
--> src\main.rs:3:13
|
3 | let _ = "x" as Arc;
| ^^^^^^^^^^^^^^^ help: consider using the From trait instead: Arc<str>::from("x")
error[E0605]: non-primitive cast: i32 as Option<i32>
--> src\main.rs:4:13
|
4 | let _ = 2 as Option;
which looks horrible to be honest
so i made a small fix that make errors looks like this
error[E0605]: non-primitive cast: &'static str as Arc<str>
|
3 | let _ = "x" as Arc;
| ^^^^^^^^^^^^^^^
|
= note: an as expression can only be used to convert between primitive types or to coerce to a specific trait object
help: consider using the From trait instead
|
3 - let _ = "x" as Arc;
3 + let _ = Arc::::from("x");
|
error[E0605]: non-primitive cast: i32 as Option<i32>
|
4 | let _ = 2 as Option;
| ^^^^^^^^^^^^^^^^
|
= note: an as expression can only be used to convert between primitive types or to coerce to a specific trait object
help: consider using the From trait instead
|
4 - let _ = 2 as Option;
4 + let _ = Option::::from(2);
What improves?
Arc<str>::from("x")which makes no sense because of missing::- readability
Related Issue
fixes #135412