mirror of https://github.com/rust-lang/rust
59 lines
2.9 KiB
Plaintext
59 lines
2.9 KiB
Plaintext
error: captured variable cannot escape `FnMut` closure body
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--> $DIR/issue-95079-missing-move-in-nested-closure.rs:5:29
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LL | fn foo1(s: &str) -> impl Iterator<Item = String> + '_ {
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| - variable defined here
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LL | None.into_iter()
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LL | .flat_map(move |()| s.chars().map(|c| format!("{}{}", c, s)))
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| - -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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| | |
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| | returns a closure that contains a reference to a captured variable, which then escapes the closure body
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| | variable captured here
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| inferred to be a `FnMut` closure
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= note: `FnMut` closures only have access to their captured variables while they are executing...
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= note: ...therefore, they cannot allow references to captured variables to escape
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help: consider adding 'move' keyword before the nested closure
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LL | .flat_map(move |()| s.chars().map(move |c| format!("{}{}", c, s)))
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| ++++
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error: lifetime may not live long enough
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--> $DIR/issue-95079-missing-move-in-nested-closure.rs:11:15
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LL | move |()| s.chars().map(|c| format!("{}{}", c, s))
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| --------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ returning this value requires that `'1` must outlive `'2`
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| | |
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| | return type of closure `Map<Chars<'_>, {closure@$DIR/issue-95079-missing-move-in-nested-closure.rs:11:29: 11:32}>` contains a lifetime `'2`
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| lifetime `'1` represents this closure's body
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= note: closure implements `Fn`, so references to captured variables can't escape the closure
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help: consider adding 'move' keyword before the nested closure
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LL | move |()| s.chars().map(move |c| format!("{}{}", c, s))
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| ++++
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error: captured variable cannot escape `FnMut` closure body
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--> $DIR/issue-95079-missing-move-in-nested-closure.rs:21:9
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LL | bar: &'a X,
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| --- variable defined here
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LL | ) -> impl Iterator<Item = ()> + 'a {
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LL | Some(()).iter().flat_map(move |()| {
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| - inferred to be a `FnMut` closure
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LL | Some(()).iter().map(|()| { bar; })
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^---^^^^
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| | |
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| | variable captured here
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| returns a closure that contains a reference to a captured variable, which then escapes the closure body
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= note: `FnMut` closures only have access to their captured variables while they are executing...
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= note: ...therefore, they cannot allow references to captured variables to escape
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help: consider adding 'move' keyword before the nested closure
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LL | Some(()).iter().map(move |()| { bar; })
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| ++++
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error: aborting due to 3 previous errors
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