| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:7:35 |
| | |
| LL | fn fuz() -> (usize, Trait) { (42, Struct) } |
| | ^^^^^^ expected trait object `dyn Trait`, found struct `Struct` |
| | |
| = note: expected trait object `(dyn Trait + 'static)` |
| found struct `Struct` |
| |
| 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 `std::marker::Sized` is not implemented for `(dyn Trait + 'static)` |
| = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait> |
| = 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 trait object `dyn Trait`, found struct `Struct` |
| | |
| = note: expected trait object `(dyn Trait + 'static)` |
| found struct `Struct` |
| |
| 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 `std::marker::Sized` is not implemented for `(dyn Trait + 'static)` |
| = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait> |
| = 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 |
| | |
| = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits> |
| help: use `impl Trait` as the return type, as all return paths are of type `Struct`, which implements `Trait` |
| | |
| LL | fn bap() -> impl Trait { 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 |
| | |
| = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits> |
| help: use `impl Trait` as the return type, as all return paths are of type `Struct`, which implements `Trait` |
| | |
| LL | fn ban() -> impl Trait { 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: use some type `T` that is `T: Sized` as the return type if all return paths have the same type |
| | |
| LL | fn bak() -> T { unimplemented!() } |
| | ^ |
| help: use `impl Trait` as the return type if all return paths have the same type but you want to expose only the trait in the signature |
| | |
| LL | fn bak() -> impl Trait { unimplemented!() } |
| | ^^^^^^^^^^ |
| help: use a boxed trait object if all return paths implement trait `Trait` |
| | |
| LL | fn bak() -> Box<dyn Trait> { 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 |
| | |
| = 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 Trait` 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 bal() -> Box<dyn Trait> { |
| LL | if true { |
| LL | return Box::new(Struct); |
| LL | } |
| LL | Box::new(42) |
| | |
| |
| error[E0308]: `if` and `else` have incompatible types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:29:9 |
| | |
| LL | / if true { |
| LL | | Struct |
| | | ------ expected because of this |
| LL | | } else { |
| LL | | 42 |
| | | ^^ expected struct `Struct`, found integer |
| LL | | } |
| | |_____- `if` and `else` have incompatible types |
| |
| 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 |
| | |
| = 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 Trait` 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 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 `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| LL | if true { |
| LL | return Struct; |
| | ^^^^^^ |
| | | |
| | expected struct `std::boxed::Box`, found struct `Struct` |
| | help: store this in the heap by calling `Box::new`: `Box::new(Struct)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:36:5 |
| | |
| LL | fn bam() -> Box<dyn Trait> { |
| | -------------- expected `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| ... |
| LL | 42 |
| | ^^ |
| | | |
| | expected struct `std::boxed::Box`, found integer |
| | help: store this in the heap by calling `Box::new`: `Box::new(42)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:40:16 |
| | |
| LL | fn baq() -> Box<dyn Trait> { |
| | -------------- expected `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| LL | if true { |
| LL | return 0; |
| | ^ |
| | | |
| | expected struct `std::boxed::Box`, found integer |
| | help: store this in the heap by calling `Box::new`: `Box::new(0)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:42:5 |
| | |
| LL | fn baq() -> Box<dyn Trait> { |
| | -------------- expected `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| ... |
| LL | 42 |
| | ^^ |
| | | |
| | expected struct `std::boxed::Box`, found integer |
| | help: store this in the heap by calling `Box::new`: `Box::new(42)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:46:9 |
| | |
| LL | fn baz() -> Box<dyn Trait> { |
| | -------------- expected `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| LL | if true { |
| LL | Struct |
| | ^^^^^^ |
| | | |
| | expected struct `std::boxed::Box`, found struct `Struct` |
| | help: store this in the heap by calling `Box::new`: `Box::new(Struct)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:48:9 |
| | |
| LL | fn baz() -> Box<dyn Trait> { |
| | -------------- expected `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| ... |
| LL | 42 |
| | ^^ |
| | | |
| | expected struct `std::boxed::Box`, found integer |
| | help: store this in the heap by calling `Box::new`: `Box::new(42)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:53:9 |
| | |
| LL | fn baw() -> Box<dyn Trait> { |
| | -------------- expected `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| LL | if true { |
| LL | 0 |
| | ^ |
| | | |
| | expected struct `std::boxed::Box`, found integer |
| | help: store this in the heap by calling `Box::new`: `Box::new(0)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| error[E0308]: mismatched types |
| --> $DIR/dyn-trait-return-should-be-impl-trait.rs:55:9 |
| | |
| LL | fn baw() -> Box<dyn Trait> { |
| | -------------- expected `std::boxed::Box<(dyn Trait + 'static)>` because of return type |
| ... |
| LL | 42 |
| | ^^ |
| | | |
| | expected struct `std::boxed::Box`, found integer |
| | help: store this in the heap by calling `Box::new`: `Box::new(42)` |
| | |
| = note: expected struct `std::boxed::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 |
| |
| 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 |
| | |
| = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits> |
| help: use `impl Trait` as the return type, as all return paths are of type `{integer}`, which implements `Trait` |
| | |
| LL | fn bat() -> impl Trait { |
| | ^^^^^^^^^^ |
| |
| 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 |
| | |
| = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits> |
| help: use `impl Trait` as the return type, as all return paths are of type `{integer}`, which implements `Trait` |
| | |
| LL | fn bay() -> impl Trait { |
| | ^^^^^^^^^^ |
| |
| error: aborting due to 20 previous errors |
| |
| Some errors have detailed explanations: E0277, E0308, E0746. |
| For more information about an error, try `rustc --explain E0277`. |