mirror of https://github.com/rust-lang/rust
41 lines
2.1 KiB
Plaintext
41 lines
2.1 KiB
Plaintext
error[E0038]: the trait `Foo` cannot be made into an object
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--> $DIR/arbitrary-self-types-not-object-safe.rs:33:32
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LL | fn foo(self: &Rc<Self>) -> usize;
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| --------- help: consider changing method `foo`'s `self` parameter to be `&self`: `&Self`
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...
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LL | let x = Rc::new(5usize) as Rc<dyn Foo>;
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| ^^^^^^^^^^^ `Foo` cannot be made into an object
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note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
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--> $DIR/arbitrary-self-types-not-object-safe.rs:8:18
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LL | trait Foo {
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| --- this trait cannot be made into an object...
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LL | fn foo(self: &Rc<Self>) -> usize;
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| ^^^^^^^^^ ...because method `foo`'s `self` parameter cannot be dispatched on
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= help: only type `usize` implements the trait, consider using it directly instead
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error[E0038]: the trait `Foo` cannot be made into an object
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--> $DIR/arbitrary-self-types-not-object-safe.rs:33:13
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LL | fn foo(self: &Rc<Self>) -> usize;
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| --------- help: consider changing method `foo`'s `self` parameter to be `&self`: `&Self`
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...
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LL | let x = Rc::new(5usize) as Rc<dyn Foo>;
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| ^^^^^^^^^^^^^^^ `Foo` cannot be made into an object
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note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
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--> $DIR/arbitrary-self-types-not-object-safe.rs:8:18
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LL | trait Foo {
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| --- this trait cannot be made into an object...
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LL | fn foo(self: &Rc<Self>) -> usize;
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| ^^^^^^^^^ ...because method `foo`'s `self` parameter cannot be dispatched on
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= help: only type `usize` implements the trait, consider using it directly instead
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= note: required for the cast from `Rc<usize>` to `Rc<dyn Foo>`
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error: aborting due to 2 previous errors
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For more information about this error, try `rustc --explain E0038`.
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