rust/tests/ui/str/str-concat-on-double-ref.rs

fn main() {
    let a: &String = &"1".to_owned();
    let b: &str = &"2";
    let c = a + b;
    //~^ ERROR cannot add `&str` to `&String`
    println!("{:?}", c);
}
Detect double reference when applying binary op ```rust let vr = v.iter().filter(\|x\| { x % 2 == 0 }); ``` will now yield the following compiler output: ```bash ERROR binary operation `%` cannot be applied to type `&&_` NOTE this is a reference of a reference to a type that `%` can be applied to, you need to dereference this variable once for this operation to work NOTE an implementation of `std::ops::Rem` might be missing for `&&_` ``` The first NOTE is new. Bug #33877 2016-06-23 01:29:16 +00:00			`fn main() {`
			`let a: &String = &"1".to_owned();`
			`let b: &str = &"2";`
			`let c = a + b;`
pretty: trim paths of unique symbols If a symbol name can only be imported from one place for a type, and as long as it was not glob-imported anywhere in the current crate, we can trim its printed path and print only the name. This has wide implications on error messages with types, for example, shortening `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable anywhere. This adds a new '-Z trim-diagnostic-paths=false' option to control this feature. On the good path, with no diagnosis printed, we should try to avoid issuing this query, so we need to prevent trimmed_def_paths query on several cases. This change also relies on a previous commit that differentiates between `Debug` and `Display` on various rustc types, where the latter is trimmed and presented to the user and the former is not. 2020-09-02 07:40:56 +00:00			//~^ ERROR cannot add `&str` to `&String`
Detect double reference when applying binary op ```rust let vr = v.iter().filter(\|x\| { x % 2 == 0 }); ``` will now yield the following compiler output: ```bash ERROR binary operation `%` cannot be applied to type `&&_` NOTE this is a reference of a reference to a type that `%` can be applied to, you need to dereference this variable once for this operation to work NOTE an implementation of `std::ops::Rem` might be missing for `&&_` ``` The first NOTE is new. Bug #33877 2016-06-23 01:29:16 +00:00			`println!("{:?}", c);`
			`}`