28 lines
915 B
Rust
28 lines
915 B
Rust
// Test that a type which is covariant with respect to its region
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// parameter yields an error when used in a contravariant way.
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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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// This is contravariant with respect to 'a, meaning that
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// Contravariant<'long> <: Contravariant<'short> iff
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// 'short <= 'long
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struct Contravariant<'a> {
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f: &'a isize
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}
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fn use_<'short,'long>(c: Contravariant<'short>,
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s: &'short isize,
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l: &'long isize,
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_where:Option<&'short &'long ()>) {
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// Test whether Contravariant<'short> <: Contravariant<'long>. Since
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// 'short <= 'long, this would be true if the Contravariant type were
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// covariant with respect to its parameter 'a.
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let _: Contravariant<'long> = 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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