mirror of https://github.com/rust-lang/book
17 lines
846 B
Plaintext
17 lines
846 B
Plaintext
$ cargo build
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Compiling functions-example v0.1.0 (file:///projects/functions-example)
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error[E0746]: return type cannot have an unboxed trait object
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--> src/lib.rs:1:25
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1 | fn returns_closure() -> dyn Fn(i32) -> i32 {
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| ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
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= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
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help: use `impl Fn(i32) -> i32` as the return type, as all return paths are of type `[closure@src/lib.rs:2:5: 2:14]`, which implements `Fn(i32) -> i32`
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1 | fn returns_closure() -> impl Fn(i32) -> i32 {
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| ~~~~~~~~~~~~~~~~~~~
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For more information about this error, try `rustc --explain E0746`.
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error: could not compile `functions-example` due to previous error
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