mirror of https://github.com/rust-lang/rust
22 lines
620 B
Rust
22 lines
620 B
Rust
// Test that a type which is invariant with respect to its region
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// parameter used in a covariant way yields an error.
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//
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// Note: see variance-regions-*.rs for the tests that check that the
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// variance inference works in the first place.
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struct Invariant<'a> {
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f: &'a mut &'a isize
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}
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fn use_<'b>(c: Invariant<'b>) {
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// For this assignment to be legal, Invariant<'b> <: Invariant<'static>.
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// Since 'b <= 'static, this would be true if Invariant were covariant
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// with respect to its parameter 'a.
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let _: Invariant<'static> = c;
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//~^ ERROR lifetime may not live long enough
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}
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fn main() { }
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