mirror of https://github.com/rust-lang/rust
44 lines
1.6 KiB
Plaintext
44 lines
1.6 KiB
Plaintext
error[E0308]: mismatched types
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--> $DIR/regions-lifetime-bounds-on-fns.rs:20:43
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LL | let _: fn(&mut &isize, &mut &isize) = a;
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| ---------------------------- ^ one type is more general than the other
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| |
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| expected due to this
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= note: expected fn pointer `for<'a, 'b, 'c, 'd> fn(&'a mut &'b _, &'c mut &'d _)`
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found fn item `for<'a, 'b> fn(&'a mut &_, &'b mut &_) {a::<'_, '_>}`
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error: lifetime may not live long enough
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--> $DIR/regions-lifetime-bounds-on-fns.rs:8:5
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LL | fn b<'a, 'b>(x: &mut &'a isize, y: &mut &'b isize) {
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| -- -- lifetime `'b` defined here
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| |
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| lifetime `'a` defined here
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LL | // Illegal now because there is no `'b:'a` declaration.
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LL | *x = *y;
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| ^^^^^^^ assignment requires that `'b` must outlive `'a`
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= help: consider adding the following bound: `'b: 'a`
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error: lifetime may not live long enough
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--> $DIR/regions-lifetime-bounds-on-fns.rs:14:5
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LL | fn c<'a,'b>(x: &mut &'a isize, y: &mut &'b isize) {
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| -- -- lifetime `'b` defined here
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| |
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| lifetime `'a` defined here
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...
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LL | a(x, y);
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| ^^^^^^^ argument requires that `'b` must outlive `'a`
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= help: consider adding the following bound: `'b: 'a`
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= note: requirement occurs because of a mutable reference to `&isize`
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= note: mutable references are invariant over their type parameter
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= help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
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error: aborting due to 3 previous errors
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For more information about this error, try `rustc --explain E0308`.
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