|
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
- = help: you can instead return a boxed trait object using `Box<dyn std::fmt::Display>`
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
- = help: alternatively, create a new `enum` with a variant for each returned type
+ = help: you could instead create a new `enum` with a variant for each returned type
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn foo() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | return Box::new(0i32);
+LL | }
+LL | Box::new(1u32)
+ |
error[E0308]: mismatched types
- --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:13:16
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:12:16
|
LL | fn bar() -> impl std::fmt::Display {
| ---------------------- expected because this return type...
|
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
- = help: you can instead return a boxed trait object using `Box<dyn std::fmt::Display>`
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
- = help: alternatively, create a new `enum` with a variant for each returned type
+ = help: you could instead create a new `enum` with a variant for each returned type
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn bar() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | return Box::new(0i32);
+LL | } else {
+LL | return Box::new(1u32);
+ |
error[E0308]: mismatched types
- --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:22:9
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:20:9
|
LL | fn baz() -> impl std::fmt::Display {
| ---------------------- expected because this return type...
|
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
- = help: you can instead return a boxed trait object using `Box<dyn std::fmt::Display>`
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
- = help: alternatively, create a new `enum` with a variant for each returned type
+ = help: you could instead create a new `enum` with a variant for each returned type
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn baz() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | return Box::new(0i32);
+LL | } else {
+LL | Box::new(1u32)
+ |
error[E0308]: `if` and `else` have incompatible types
- --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:31:9
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:28:9
|
LL | / if false {
LL | | 0i32
LL | | } else {
LL | | 1u32
| | ^^^^ expected `i32`, found `u32`
-LL | |
LL | | }
| |_____- `if` and `else` have incompatible types
+ |
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn qux() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | Box::new(0i32)
+LL | } else {
+LL | Box::new(1u32)
+ |
error[E0308]: mismatched types
- --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:39:14
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:35:14
|
LL | fn bat() -> impl std::fmt::Display {
| ---------------------- expected because this return type...
|
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
- = help: you can instead return a boxed trait object using `Box<dyn std::fmt::Display>`
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
- = help: alternatively, create a new `enum` with a variant for each returned type
+ = help: you could instead create a new `enum` with a variant for each returned type
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn bat() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | 0 => return Box::new(0i32),
+LL | _ => Box::new(1u32),
+ |
error[E0308]: mismatched types
- --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:45:5
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:40:5
|
LL | fn can() -> impl std::fmt::Display {
| ---------------------- expected because this return type...
LL | / match 13 {
-LL | |
LL | | 0 => return 0i32,
| | ---- ...is found to be `i32` here
LL | | 1 => 1u32,
|
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
- = help: you can instead return a boxed trait object using `Box<dyn std::fmt::Display>`
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
- = help: alternatively, create a new `enum` with a variant for each returned type
+ = help: you could instead create a new `enum` with a variant for each returned type
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn can() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | Box::new(match 13 {
+LL | 0 => return Box::new(0i32),
+LL | 1 => 1u32,
+LL | _ => 2u32,
+LL | })
+ |
error[E0308]: mismatched types
- --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:59:13
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:53:13
|
LL | fn cat() -> impl std::fmt::Display {
| ---------------------- expected because this return type...
|
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
- = help: you can instead return a boxed trait object using `Box<dyn std::fmt::Display>`
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
- = help: alternatively, create a new `enum` with a variant for each returned type
+ = help: you could instead create a new `enum` with a variant for each returned type
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn cat() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | return Box::new(0i32);
+LL | }
+LL | _ => {
+LL | Box::new(1u32)
+ |
+
+error[E0308]: `match` arms have incompatible types
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:61:14
+ |
+LL | / match 13 {
+LL | | 0 => 0i32,
+ | | ---- this is found to be of type `i32`
+LL | | 1 => 1u32,
+ | | ^^^^ expected `i32`, found `u32`
+LL | | _ => 2u32,
+LL | | }
+ | |_____- `match` arms have incompatible types
+ |
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn dog() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | 0 => Box::new(0i32),
+LL | 1 => Box::new(1u32),
+ |
+
+error[E0308]: `if` and `else` have incompatible types
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:97:9
+ |
+LL | / if let Some(42) = Some(42) {
+LL | | 0i32
+ | | ---- expected because of this
+LL | | } else {
+LL | | 1u32
+ | | ^^^^ expected `i32`, found `u32`
+LL | | }
+ | |_____- `if` and `else` have incompatible types
+ |
+help: you could change the return type to be a boxed trait object
+ |
+LL | fn apt() -> Box<dyn std::fmt::Display> {
+ | ^^^^^^^ ^
+help: if you change the return type to expect trait objects, box the returned expressions
+ |
+LL | Box::new(0i32)
+LL | } else {
+LL | Box::new(1u32)
+ |
+
+error[E0746]: return type cannot have an unboxed trait object
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:66:13
+ |
+LL | fn hat() -> dyn std::fmt::Display {
+ | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+ |
+ = note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
+ = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type
+ = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
+ = note: you can create a new `enum` with a variant for each returned type
+help: return a boxed trait object instead
+ |
+LL | fn hat() -> Box<dyn std::fmt::Display> {
+LL | match 13 {
+LL | 0 => {
+LL | return Box::new(0i32);
+LL | }
+LL | _ => {
+ ...
+
+error[E0308]: `match` arms have incompatible types
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:80:14
+ |
+LL | / match 13 {
+LL | | 0 => 0i32,
+ | | ---- this is found to be of type `i32`
+LL | | 1 => 1u32,
+ | | ^^^^ expected `i32`, found `u32`
+LL | | _ => 2u32,
+LL | | }
+ | |_____- `match` arms have incompatible types
+
+error[E0746]: return type cannot have an unboxed trait object
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:77:13
+ |
+LL | fn pug() -> dyn std::fmt::Display {
+ | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+ |
+ = note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
+ = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type
+ = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
+ = note: you can create a new `enum` with a variant for each returned type
+help: return a boxed trait object instead
+ |
+LL | fn pug() -> Box<dyn std::fmt::Display> {
+LL | match 13 {
+LL | 0 => Box::new(0i32),
+LL | 1 => Box::new(1u32),
+LL | _ => Box::new(2u32),
+ |
+
+error[E0308]: `if` and `else` have incompatible types
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:89:9
+ |
+LL | / if false {
+LL | | 0i32
+ | | ---- expected because of this
+LL | | } else {
+LL | | 1u32
+ | | ^^^^ expected `i32`, found `u32`
+LL | | }
+ | |_____- `if` and `else` have incompatible types
+
+error[E0746]: return type cannot have an unboxed trait object
+ --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:85:13
+ |
+LL | fn man() -> dyn std::fmt::Display {
+ | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+ |
+ = note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
+ = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type
+ = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
+ = note: you can create a new `enum` with a variant for each returned type
+help: return a boxed trait object instead
+ |
+LL | fn man() -> Box<dyn std::fmt::Display> {
+LL | if false {
+LL | Box::new(0i32)
+LL | } else {
+LL | Box::new(1u32)
+ |
-error: aborting due to 7 previous errors
+error: aborting due to 14 previous errors
-For more information about this error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0308, E0746.
+For more information about an error, try `rustc --explain E0308`.
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