mirror of https://github.com/rust-lang/rust
29 lines
777 B
Rust
29 lines
777 B
Rust
// Test that attempt to mutably borrow `&mut` pointer while pointee is
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// borrowed yields an error.
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//
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// Example from compiler/rustc_borrowck/borrowck/README.md
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fn foo<'a>(mut t0: &'a mut isize,
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mut t1: &'a mut isize) {
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let p: &isize = &*t0; // Freezes `*t0`
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let mut t2 = &mut t0; //~ ERROR cannot borrow `t0`
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**t2 += 1; // Mutates `*t0`
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p.use_ref();
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}
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fn bar<'a>(mut t0: &'a mut isize,
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mut t1: &'a mut isize) {
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let p: &mut isize = &mut *t0; // Claims `*t0`
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let mut t2 = &mut t0; //~ ERROR cannot borrow `t0`
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**t2 += 1; // Mutates `*t0` but not through `*p`
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p.use_mut();
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}
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fn main() {
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}
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trait Fake { fn use_mut(&mut self) { } fn use_ref(&self) { } }
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impl<T> Fake for T { }
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