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Diffstat (limited to 'tests/ui/impl-trait/multiple-lifetimes/ordinary-bounds-unrelated.rs')
-rw-r--r-- | tests/ui/impl-trait/multiple-lifetimes/ordinary-bounds-unrelated.rs | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/tests/ui/impl-trait/multiple-lifetimes/ordinary-bounds-unrelated.rs b/tests/ui/impl-trait/multiple-lifetimes/ordinary-bounds-unrelated.rs new file mode 100644 index 000000000..c6eea5323 --- /dev/null +++ b/tests/ui/impl-trait/multiple-lifetimes/ordinary-bounds-unrelated.rs @@ -0,0 +1,36 @@ +// edition:2018 + +trait Trait<'a, 'b> {} +impl<T> Trait<'_, '_> for T {} + +// `Ordinary<'a> <: Ordinary<'b>` if `'a: 'b`, as with most types. +// +// I am purposefully avoiding the terms co- and contra-variant because +// their application to regions depends on how you interpreted Rust +// regions. -nikomatsakis +struct Ordinary<'a>(&'a u8); + +// Here we get an error because none of our choices (either `'d` nor `'e`) are outlived +// by both `'a` and `'b`. + +fn upper_bounds<'a, 'b, 'c, 'd, 'e>(a: Ordinary<'a>, b: Ordinary<'b>) -> impl Trait<'d, 'e> +where + 'a: 'e, + 'b: 'd, +{ + // Hidden type `Ordinary<'0>` with constraints: + // + // ``` + // 'a: '0 + // 'b: '0 + // 'a in ['d, 'e] + // ``` + if condition() { a } else { b } + //~^ ERROR hidden type for `impl Trait<'d, 'e>` captures lifetime that does not appear in bounds +} + +fn condition() -> bool { + true +} + +fn main() {} |