ICE when pattern matching on &dyn PartialEq. #72565
Description
const F: &'static dyn PartialEq<u32> = &7u32; fn main() { let a: &dyn PartialEq<u32> = &7u32; match a { F => panic!(), _ => {} } }causes an ICE on the current nightly
error: internal compiler error: src/librustc_mir_build/hair/pattern/_match.rs:363: cannot deref ByRef { alloc: Allocation { bytes: [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ], relocations: Relocations( SortedMap { data: [ ( Size { raw: 0, }, ( (), a2, ), ), ( Size { raw: 8, }, ( (), a4, ), ), ], }, ), init_mask: InitMask { blocks: [ 65535, ], len: Size { raw: 16, }, }, size: Size { raw: 16, }, align: Align { pow2: 3, }, mutability: Not, extra: (), }, offset: Size { raw: 0, }, }, dyn std::cmp::PartialEq<u32> -> dyn std::cmp::PartialEq<u32> thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:907:9 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace Afaik this is caused by ty_is_partial_eq being slightly too permissive
rust/src/librustc_mir_build/hair/pattern/const_to_pat.rs
Lines 143 to 157 in 997d953
See #71038 (comment) for more details.