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rust/tests/ui/suggestions/chain-method-call-mutation-in-place.stderr

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Add explanation for `&mut self` method call when expecting `-> Self` When a user tries to use a method as if it returned a new value of the same type as its receiver, we will emit a type error. Try to detect this and provide extra explanation that the method modifies the receiver in-place. This has confused people in the wild, like in https://users.rust-lang.org/t/newbie-why-the-commented-line-stops-the-snippet-from-compiling/47322
2020-08-16 20:33:30 -05:00
error[E0308]: mismatched types
Emit "modifies receiver" diagnostic when no method is found If no method is found when checking method call, we check if we called a method with signature (&mut T, ...) -> (). If this is the case then we emit a diagnostic message
2023-03-14 08:12:47 -05:00
--> $DIR/chain-method-call-mutation-in-place.rs:2:23
|
LL | let x: Vec<i32> = vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i);
| -------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Vec<i32>`, found `()`
| |
| expected due to this
|
= note: expected struct `Vec<i32>`
found unit type `()`
note: method `sort_by_key` modifies its receiver in-place, it is not meant to be used in method chains.
--> $DIR/chain-method-call-mutation-in-place.rs:2:71
|
LL | let x: Vec<i32> = vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i);
| ^^^^^^^^^^^ this call modifies its receiver in-place
error[E0599]: no method named `sort` found for unit type `()` in the current scope
--> $DIR/chain-method-call-mutation-in-place.rs:3:72
|
LL | vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i).sort();
| ^^^^ method not found in `()`
|
note: method `sort_by_key` modifies its receiver in-place, it is not meant to be used in method chains.
--> $DIR/chain-method-call-mutation-in-place.rs:3:53
|
LL | vec![1, 2, 3].into_iter().collect::<Vec<i32>>().sort_by_key(|i| i).sort();
| ^^^^^^^^^^^ this call modifies its receiver in-place
error[E0308]: mismatched types
--> $DIR/chain-method-call-mutation-in-place.rs:7:5
Add explanation for `&mut self` method call when expecting `-> Self` When a user tries to use a method as if it returned a new value of the same type as its receiver, we will emit a type error. Try to detect this and provide extra explanation that the method modifies the receiver in-place. This has confused people in the wild, like in https://users.rust-lang.org/t/newbie-why-the-commented-line-stops-the-snippet-from-compiling/47322
2020-08-16 20:33:30 -05:00
|
LL | fn foo(mut s: String) -> String {
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 02:40:56 -05:00
| ------ expected `String` because of return type
Add explanation for `&mut self` method call when expecting `-> Self` When a user tries to use a method as if it returned a new value of the same type as its receiver, we will emit a type error. Try to detect this and provide extra explanation that the method modifies the receiver in-place. This has confused people in the wild, like in https://users.rust-lang.org/t/newbie-why-the-commented-line-stops-the-snippet-from-compiling/47322
2020-08-16 20:33:30 -05:00
LL | s.push_str("asdf")
Modify primary span label for E0308 The previous output was unintuitive to users.
2023-01-02 20:00:33 -06:00
| ^^^^^^^^^^^^^^^^^^ expected `String`, found `()`
Add explanation for `&mut self` method call when expecting `-> Self` When a user tries to use a method as if it returned a new value of the same type as its receiver, we will emit a type error. Try to detect this and provide extra explanation that the method modifies the receiver in-place. This has confused people in the wild, like in https://users.rust-lang.org/t/newbie-why-the-commented-line-stops-the-snippet-from-compiling/47322
2020-08-16 20:33:30 -05:00
|
note: method `push_str` modifies its receiver in-place
Emit "modifies receiver" diagnostic when no method is found If no method is found when checking method call, we check if we called a method with signature (&mut T, ...) -> (). If this is the case then we emit a diagnostic message
2023-03-14 08:12:47 -05:00
--> $DIR/chain-method-call-mutation-in-place.rs:7:7
Add explanation for `&mut self` method call when expecting `-> Self` When a user tries to use a method as if it returned a new value of the same type as its receiver, we will emit a type error. Try to detect this and provide extra explanation that the method modifies the receiver in-place. This has confused people in the wild, like in https://users.rust-lang.org/t/newbie-why-the-commented-line-stops-the-snippet-from-compiling/47322
2020-08-16 20:33:30 -05:00
|
LL | s.push_str("asdf")
| - ^^^^^^^^ this call modifies `s` in-place
| |
| you probably want to use this value after calling the method...
= note: ...instead of the `()` output of method `push_str`
Emit "modifies receiver" diagnostic when no method is found If no method is found when checking method call, we check if we called a method with signature (&mut T, ...) -> (). If this is the case then we emit a diagnostic message
2023-03-14 08:12:47 -05:00
error: aborting due to 3 previous errors
Add explanation for `&mut self` method call when expecting `-> Self` When a user tries to use a method as if it returned a new value of the same type as its receiver, we will emit a type error. Try to detect this and provide extra explanation that the method modifies the receiver in-place. This has confused people in the wild, like in https://users.rust-lang.org/t/newbie-why-the-commented-line-stops-the-snippet-from-compiling/47322
2020-08-16 20:33:30 -05:00
Emit "modifies receiver" diagnostic when no method is found If no method is found when checking method call, we check if we called a method with signature (&mut T, ...) -> (). If this is the case then we emit a diagnostic message
2023-03-14 08:12:47 -05:00
Some errors have detailed explanations: E0308, E0599.
For more information about an error, try `rustc --explain E0308`.
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