From 218caa410aa38c29984be31a5229b9fa717560ee Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:13 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- ...regions-variance-contravariant-use-covariant.rs | 27 ++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 tests/ui/regions/regions-variance-contravariant-use-covariant.rs (limited to 'tests/ui/regions/regions-variance-contravariant-use-covariant.rs') diff --git a/tests/ui/regions/regions-variance-contravariant-use-covariant.rs b/tests/ui/regions/regions-variance-contravariant-use-covariant.rs new file mode 100644 index 000000000..c73577cb3 --- /dev/null +++ b/tests/ui/regions/regions-variance-contravariant-use-covariant.rs @@ -0,0 +1,27 @@ +// Test that a type which is covariant with respect to its region +// parameter yields an error when used in a contravariant way. +// +// Note: see variance-regions-*.rs for the tests that check that the +// variance inference works in the first place. + +// This is contravariant with respect to 'a, meaning that +// Contravariant<'long> <: Contravariant<'short> iff +// 'short <= 'long +struct Contravariant<'a> { + f: &'a isize +} + +fn use_<'short,'long>(c: Contravariant<'short>, + s: &'short isize, + l: &'long isize, + _where:Option<&'short &'long ()>) { + + // Test whether Contravariant<'short> <: Contravariant<'long>. Since + // 'short <= 'long, this would be true if the Contravariant type were + // covariant with respect to its parameter 'a. + + let _: Contravariant<'long> = c; + //~^ ERROR lifetime may not live long enough +} + +fn main() {} -- cgit v1.2.3