mirror of https://github.com/rust-lang/rust
39 lines
714 B
Rust
39 lines
714 B
Rust
#[derive(Debug)]
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struct X<T>(T);
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impl<T: Clone> Clone for X<T> {
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fn clone(&self) -> X<T> {
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X(self.0.clone())
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}
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}
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#[derive(Debug)]
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struct Y;
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#[derive(Debug)]
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struct Str {
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x: Option<i32>,
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}
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fn foo(s: &mut Option<i32>) {
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if s.is_none() {
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*s = Some(0);
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}
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println!("{:?}", s);
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}
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fn bar<T: std::fmt::Debug>(s: &mut X<T>) {
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println!("{:?}", s);
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}
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fn main() {
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let s = Str { x: None };
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let sr = &s;
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let mut sm = sr.clone();
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foo(&mut sm.x); //~ ERROR cannot borrow `sm.x` as mutable, as it is behind a `&` reference
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let x = X(Y);
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let xr = &x;
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let mut xm = xr.clone();
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bar(&mut xm); //~ ERROR cannot borrow data in a `&` reference as mutable
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}
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