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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
commit | 218caa410aa38c29984be31a5229b9fa717560ee (patch) | |
tree | c54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/regions/regions-scope-chain-example.rs | |
parent | Releasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/regions/regions-scope-chain-example.rs')
-rw-r--r-- | tests/ui/regions/regions-scope-chain-example.rs | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/tests/ui/regions/regions-scope-chain-example.rs b/tests/ui/regions/regions-scope-chain-example.rs new file mode 100644 index 000000000..2beb20add --- /dev/null +++ b/tests/ui/regions/regions-scope-chain-example.rs @@ -0,0 +1,43 @@ +// run-pass +#![allow(dead_code)] +#![allow(unused_variables)] +// This is an example where the older inference algorithm failed. The +// specifics of why it failed are somewhat, but not entirely, tailed +// to the algorithm. Ultimately the problem is that when computing the +// mutual supertype of both sides of the `if` it would be faced with a +// choice of tightening bounds or unifying variables and it took the +// wrong path. The new algorithm avoids this problem and hence this +// example typechecks correctly. + +// pretty-expanded FIXME #23616 + +enum ScopeChain<'a> { + Link(Scope<'a>), + End +} + +type Scope<'a> = &'a ScopeChain<'a>; + +struct OuterContext; + +struct Context<'a> { + foo: &'a OuterContext +} + +impl<'a> Context<'a> { + fn foo(&mut self, scope: Scope) { + let link = if 1 < 2 { + let l = ScopeChain::Link(scope); + self.take_scope(&l); + l + } else { + ScopeChain::Link(scope) + }; + self.take_scope(&link); + } + + fn take_scope(&mut self, x: Scope) { + } +} + +fn main() { } |