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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:06:31 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:06:31 +0000
commit2ff14448863ac1a1dd9533461708e29aae170c2d (patch)
tree85b9fea2bbfe3f06473cfa381eed11f273b57c5c /src/test/ui/higher-rank-trait-bounds/issue-57639.rs
parentAdding debian version 1.64.0+dfsg1-1. (diff)
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Adding debian version 1.65.0+dfsg1-2.debian/1.65.0+dfsg1-2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+// Regression test for #57639:
+//
+// In the move to universes, this test stopped working. The problem
+// was that when the trait solver was asked to prove `for<'a> T::Item:
+// Foo<'a>` as part of WF checking, it wound up "eagerly committing"
+// to the where clause, which says that `T::Item: Foo<'a>`, but it
+// should instead have been using the bound found in the trait
+// declaration. Pre-universe, this used to work out ok because we got
+// "eager errors" due to the leak check.
+//
+// See [this comment on GitHub][c] for more details.
+//
+// check-pass
+//
+// [c]: https://github.com/rust-lang/rust/issues/57639#issuecomment-455685861
+
+trait Foo<'a> {}
+
+trait Bar {
+ type Item: for<'a> Foo<'a>;
+}
+
+fn foo<'a, T>(_: T)
+where
+ T: Bar,
+ T::Item: Foo<'a>,
+{}
+
+fn main() { }