31 lines
910 B
Rust
31 lines
910 B
Rust
// Tests that callees correctly infer an ordering between free regions
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// that appear in their parameter list. See also
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// regions-free-region-ordering-caller.rs
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fn ordering1<'a, 'b>(x: &'a &'b usize) -> &'a usize {
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// It is safe to assume that 'a <= 'b due to the type of x
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let y: &'b usize = &**x;
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return y;
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}
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fn ordering2<'a, 'b>(x: &'a &'b usize, y: &'a usize) -> &'b usize {
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// However, it is not safe to assume that 'b <= 'a
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&*y
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//~^ ERROR lifetime may not live long enough
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}
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fn ordering3<'a, 'b>(x: &'a usize, y: &'b usize) -> &'a &'b usize {
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// Do not infer an ordering from the return value.
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let z: &'b usize = &*x;
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//~^ ERROR lifetime may not live long enough
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panic!();
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}
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// see regions-free-region-ordering-callee-4.rs
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fn ordering5<'a, 'b>(a: &'a usize, b: &'b usize, x: Option<&'a &'b usize>) {
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let z: Option<&'a &'b usize> = None;
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}
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fn main() {}
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