mirror of https://github.com/rust-lang/rust
52 lines
1.2 KiB
Rust
52 lines
1.2 KiB
Rust
// Note: the borrowck analysis is currently flow-insensitive.
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// Therefore, some of these errors are marked as spurious and could be
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// corrected by a simple change to the analysis. The others are
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// either genuine or would require more advanced changes. The latter
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// cases are noted.
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fn borrow(_v: &isize) {}
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fn borrow_mut(_v: &mut isize) {}
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fn cond() -> bool { panic!() }
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fn for_func<F>(_f: F) where F: FnOnce() -> bool { panic!() }
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fn produce<T>() -> T { panic!(); }
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fn inc(v: &mut Box<isize>) {
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*v = Box::new(**v + 1);
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}
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fn pre_freeze_cond() {
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// In this instance, the freeze is conditional and starts before
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// the mut borrow.
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let u = Box::new(0);
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let mut v: Box<_> = Box::new(3);
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let mut _w = &u;
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if cond() {
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_w = &v;
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}
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borrow_mut(&mut *v); //~ ERROR cannot borrow
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_w.use_ref();
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}
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fn pre_freeze_else() {
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// In this instance, the freeze and mut borrow are on separate sides
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// of the if.
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let u = Box::new(0);
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let mut v: Box<_> = Box::new(3);
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let mut _w = &u;
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if cond() {
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_w = &v;
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} else {
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borrow_mut(&mut *v);
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}
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_w.use_ref();
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}
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fn main() {}
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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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