48 lines
853 B
Rust
48 lines
853 B
Rust
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#![allow(unused, trivially_copy_pass_by_ref)]
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#![warn(mut_from_ref)]
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struct Foo;
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impl Foo {
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fn this_wont_hurt_a_bit(&self) -> &mut Foo {
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unimplemented!()
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}
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}
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trait Ouch {
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fn ouch(x: &Foo) -> &mut Foo;
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}
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impl Ouch for Foo {
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fn ouch(x: &Foo) -> &mut Foo {
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unimplemented!()
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}
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}
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fn fail(x: &u32) -> &mut u16 {
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unimplemented!()
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}
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fn fail_lifetime<'a>(x: &'a u32, y: &mut u32) -> &'a mut u32 {
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unimplemented!()
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}
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fn fail_double<'a, 'b>(x: &'a u32, y: &'a u32, z: &'b mut u32) -> &'a mut u32 {
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unimplemented!()
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}
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// this is OK, because the result borrows y
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fn works<'a>(x: &u32, y: &'a mut u32) -> &'a mut u32 {
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unimplemented!()
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}
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// this is also OK, because the result could borrow y
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fn also_works<'a>(x: &'a u32, y: &'a mut u32) -> &'a mut u32 {
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unimplemented!()
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}
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fn main() {
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//TODO
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}
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