5b54286640
Remove the "which is required by `{root_obligation}`" post-script in
"the trait `X` is not implemented for `Y`" explanation in E0277. This
information is already conveyed in the notes explaining requirements,
making it redundant while making the text (particularly in labels)
harder to read.
```
error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
--> $DIR/wf-static-type.rs:10:13
|
LL | static FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
| ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`
|
= note: required for `Option<NotCopy>` to implement `Copy`
note: required by a bound in `IsCopy`
--> $DIR/wf-static-type.rs:7:17
|
LL | struct IsCopy<T:Copy> { t: T }
| ^^^^ required by this bound in `IsCopy`
```
vs the prior
```
error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
--> $DIR/wf-static-type.rs:10:13
|
LL | static FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
| ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`, which is required by `Option<NotCopy>: Copy`
|
= note: required for `Option<NotCopy>` to implement `Copy`
note: required by a bound in `IsCopy`
--> $DIR/wf-static-type.rs:7:17
|
LL | struct IsCopy<T:Copy> { t: T }
| ^^^^ required by this bound in `IsCopy`
```
294 lines
12 KiB
Plaintext
294 lines
12 KiB
Plaintext
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:7:35
|
|
|
|
|
LL | fn fuz() -> (usize, Trait) { (42, Struct) }
|
|
| ^^^^^^ expected `dyn Trait`, found `Struct`
|
|
|
|
|
= note: expected trait object `(dyn Trait + 'static)`
|
|
found struct `Struct`
|
|
= help: `Struct` implements `Trait` so you could box the found value and coerce it to the trait object `Box<dyn Trait>`, you will have to change the expected type as well
|
|
|
|
error[E0277]: the size for values of type `(dyn Trait + 'static)` cannot be known at compilation time
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:7:13
|
|
|
|
|
LL | fn fuz() -> (usize, Trait) { (42, Struct) }
|
|
| ^^^^^^^^^^^^^^ ------------ this returned value is of type `(usize, (dyn Trait + 'static))`
|
|
| |
|
|
| doesn't have a size known at compile-time
|
|
|
|
|
= help: within `(usize, (dyn Trait + 'static))`, the trait `Sized` is not implemented for `(dyn Trait + 'static)`
|
|
= note: required because it appears within the type `(usize, (dyn Trait + 'static))`
|
|
= note: the return type of a function must have a statically known size
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:10:39
|
|
|
|
|
LL | fn bar() -> (usize, dyn Trait) { (42, Struct) }
|
|
| ^^^^^^ expected `dyn Trait`, found `Struct`
|
|
|
|
|
= note: expected trait object `(dyn Trait + 'static)`
|
|
found struct `Struct`
|
|
= help: `Struct` implements `Trait` so you could box the found value and coerce it to the trait object `Box<dyn Trait>`, you will have to change the expected type as well
|
|
|
|
error[E0277]: the size for values of type `(dyn Trait + 'static)` cannot be known at compilation time
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:10:13
|
|
|
|
|
LL | fn bar() -> (usize, dyn Trait) { (42, Struct) }
|
|
| ^^^^^^^^^^^^^^^^^^ ------------ this returned value is of type `(usize, (dyn Trait + 'static))`
|
|
| |
|
|
| doesn't have a size known at compile-time
|
|
|
|
|
= help: within `(usize, (dyn Trait + 'static))`, the trait `Sized` is not implemented for `(dyn Trait + 'static)`
|
|
= note: required because it appears within the type `(usize, (dyn Trait + 'static))`
|
|
= note: the return type of a function must have a statically known size
|
|
|
|
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:13:13
|
|
|
|
|
LL | fn bap() -> Trait { Struct }
|
|
| ^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
help: consider returning an `impl Trait` instead of a `dyn Trait`
|
|
|
|
|
LL | fn bap() -> impl Trait { Struct }
|
|
| ++++
|
|
help: alternatively, box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL | fn bap() -> Box<dyn Trait> { Box::new(Struct) }
|
|
| +++++++ + +++++++++ +
|
|
|
|
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:15:13
|
|
|
|
|
LL | fn ban() -> dyn Trait { Struct }
|
|
| ^^^^^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
help: consider returning an `impl Trait` instead of a `dyn Trait`
|
|
|
|
|
LL | fn ban() -> impl Trait { Struct }
|
|
| ~~~~
|
|
help: alternatively, box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL | fn ban() -> Box<dyn Trait> { Box::new(Struct) }
|
|
| ++++ + +++++++++ +
|
|
|
|
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:17:13
|
|
|
|
|
LL | fn bak() -> dyn Trait { unimplemented!() }
|
|
| ^^^^^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
help: consider returning an `impl Trait` instead of a `dyn Trait`
|
|
|
|
|
LL | fn bak() -> impl Trait { unimplemented!() }
|
|
| ~~~~
|
|
help: alternatively, box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL | fn bak() -> Box<dyn Trait> { Box::new(unimplemented!()) }
|
|
| ++++ + +++++++++ +
|
|
|
|
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:19:13
|
|
|
|
|
LL | fn bal() -> dyn Trait {
|
|
| ^^^^^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
= help: if there were a single returned type, you could use `impl Trait` instead
|
|
help: box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL ~ fn bal() -> Box<dyn Trait> {
|
|
LL | if true {
|
|
LL ~ return Box::new(Struct);
|
|
LL | }
|
|
LL ~ Box::new(42)
|
|
|
|
|
|
|
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:25:13
|
|
|
|
|
LL | fn bax() -> dyn Trait {
|
|
| ^^^^^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
= help: if there were a single returned type, you could use `impl Trait` instead
|
|
help: box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL ~ fn bax() -> Box<dyn Trait> {
|
|
LL | if true {
|
|
LL ~ Box::new(Struct)
|
|
LL | } else {
|
|
LL ~ Box::new(42)
|
|
|
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:34:16
|
|
|
|
|
LL | fn bam() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
LL | if true {
|
|
LL | return Struct;
|
|
| ^^^^^^ expected `Box<dyn Trait>`, found `Struct`
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found struct `Struct`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | return Box::new(Struct);
|
|
| +++++++++ +
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:36:5
|
|
|
|
|
LL | fn bam() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
...
|
|
LL | 42
|
|
| ^^ expected `Box<dyn Trait>`, found integer
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found type `{integer}`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | Box::new(42)
|
|
| +++++++++ +
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:40:16
|
|
|
|
|
LL | fn baq() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
LL | if true {
|
|
LL | return 0;
|
|
| ^ expected `Box<dyn Trait>`, found integer
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found type `{integer}`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | return Box::new(0);
|
|
| +++++++++ +
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:42:5
|
|
|
|
|
LL | fn baq() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
...
|
|
LL | 42
|
|
| ^^ expected `Box<dyn Trait>`, found integer
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found type `{integer}`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | Box::new(42)
|
|
| +++++++++ +
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:46:9
|
|
|
|
|
LL | fn baz() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
LL | if true {
|
|
LL | Struct
|
|
| ^^^^^^ expected `Box<dyn Trait>`, found `Struct`
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found struct `Struct`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | Box::new(Struct)
|
|
| +++++++++ +
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:48:9
|
|
|
|
|
LL | fn baz() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
...
|
|
LL | 42
|
|
| ^^ expected `Box<dyn Trait>`, found integer
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found type `{integer}`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | Box::new(42)
|
|
| +++++++++ +
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:53:9
|
|
|
|
|
LL | fn baw() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
LL | if true {
|
|
LL | 0
|
|
| ^ expected `Box<dyn Trait>`, found integer
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found type `{integer}`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | Box::new(0)
|
|
| +++++++++ +
|
|
|
|
error[E0308]: mismatched types
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:55:9
|
|
|
|
|
LL | fn baw() -> Box<dyn Trait> {
|
|
| -------------- expected `Box<(dyn Trait + 'static)>` because of return type
|
|
...
|
|
LL | 42
|
|
| ^^ expected `Box<dyn Trait>`, found integer
|
|
|
|
|
= note: expected struct `Box<(dyn Trait + 'static)>`
|
|
found type `{integer}`
|
|
= note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
|
|
help: store this in the heap by calling `Box::new`
|
|
|
|
|
LL | Box::new(42)
|
|
| +++++++++ +
|
|
|
|
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:60:13
|
|
|
|
|
LL | fn bat() -> dyn Trait {
|
|
| ^^^^^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
= help: if there were a single returned type, you could use `impl Trait` instead
|
|
help: box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL ~ fn bat() -> Box<dyn Trait> {
|
|
LL | if true {
|
|
LL ~ return Box::new(0);
|
|
LL | }
|
|
LL ~ Box::new(42)
|
|
|
|
|
|
|
error[E0746]: return type cannot have an unboxed trait object
|
|
--> $DIR/dyn-trait-return-should-be-impl-trait.rs:66:13
|
|
|
|
|
LL | fn bay() -> dyn Trait {
|
|
| ^^^^^^^^^ doesn't have a size known at compile-time
|
|
|
|
|
= help: if there were a single returned type, you could use `impl Trait` instead
|
|
help: box the return type, and wrap all of the returned values in `Box::new`
|
|
|
|
|
LL ~ fn bay() -> Box<dyn Trait> {
|
|
LL | if true {
|
|
LL ~ Box::new(0)
|
|
LL | } else {
|
|
LL ~ Box::new(42)
|
|
|
|
|
|
|
error: aborting due to 19 previous errors
|
|
|
|
Some errors have detailed explanations: E0277, E0308, E0746.
|
|
For more information about an error, try `rustc --explain E0277`.
|