Auto merge of #95315 - compiler-errors:pointee-fix, r=pnkfelix

when checking pointee metadata, canonicalize the `Sized` check

Use `infcx.predicate_must_hold_modulo_regions` with a `Sized` obligation instead of just calling `ty.is_sized`, because the latter does not canonicalize region and type vars (and in the test case I added in this PR, there's a region var in the `ParamEnv`).

Fixes #95311

1 files changed, 19 insertions, 0 deletions

diff --git a/src/test/ui/traits/issue-95311.rs b/src/test/ui/traits/issue-95311.rs
new file mode 100644
index 00000000000..9d40d254ad9
--- /dev/null
+++ b/src/test/ui/traits/issue-95311.rs
@@ -0,0 +1,19 @@
+// check-pass
+
+// Test to check that pointee trait doesn't let region variables escape into the cache
+
+#![feature(ptr_metadata)]
+
+trait Bar: Sized + 'static {}
+
+struct Foo<B: Bar> {
+    marker: std::marker::PhantomData<B>,
+}
+
+impl<B: Bar> Foo<B> {
+    fn foo<T: ?Sized>(value: &T) {
+        std::ptr::metadata(value);
+    }
+}
+
+fn main() {}