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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-lifetime-nonfree-late-bound.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-lifetime-nonfree-late-bound.rs')
-rw-r--r-- | tests/ui/regions/regions-lifetime-nonfree-late-bound.rs | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/tests/ui/regions/regions-lifetime-nonfree-late-bound.rs b/tests/ui/regions/regions-lifetime-nonfree-late-bound.rs new file mode 100644 index 000000000..3852a14d9 --- /dev/null +++ b/tests/ui/regions/regions-lifetime-nonfree-late-bound.rs @@ -0,0 +1,33 @@ +// run-pass +// This is a regression test for the ICE from issue #10846. +// +// The original issue causing the ICE: the LUB-computations during +// type inference were encountering late-bound lifetimes, and +// asserting that such lifetimes should have already been substituted +// with a concrete lifetime. +// +// However, those encounters were occurring within the lexical scope +// of the binding for the late-bound lifetime; that is, the late-bound +// lifetimes were perfectly valid. The core problem was that the type +// folding code was over-zealously passing back all lifetimes when +// doing region-folding, when really all clients of the region-folding +// case only want to see FREE lifetime variables, not bound ones. + +// pretty-expanded FIXME #23616 + +pub fn main() { + fn explicit() { + fn test<F>(_x: Option<Box<F>>) where F: FnMut(Box<dyn for<'a> FnMut(&'a isize)>) {} + test(Some(Box::new(|_f: Box<dyn for<'a> FnMut(&'a isize)>| {}))); + } + + // The code below is shorthand for the code above (and more likely + // to represent what one encounters in practice). + fn implicit() { + fn test<F>(_x: Option<Box<F>>) where F: FnMut(Box<dyn FnMut(& isize)>) {} + test(Some(Box::new(|_f: Box<dyn FnMut(& isize)>| {}))); + } + + explicit(); + implicit(); +} |