unexpected inference var in type_check/relate_tys.rs #123486
Description
Code
trait UnwrapItemsExt<'a, > {
type Iter;=
}
struct MyStruct<const C: usize> {}
trait MyTrait<'a, const C: usize> {}
impl<'a, const C: usize> MyTrait<'a, C> for MyStruct<C> {
}
impl<'a, I, const C: usize> UnwrapItemsExt<'a, C> for I {
type Iter = impl MyTrait<'a, C>;
fn unwrap_items(self) -> Self::Iter {
MyStruct::<C> {}
}
}
fn main() {} Meta
rustc --version --verbose:
rustc 1.79.0-nightly (385fa9d84 2024-04-04)
binary: rustc
commit-hash: 385fa9d845dd326c6bbfd58c22244215e431948a
commit-date: 2024-04-04
host: x86_64-apple-darwin
release: 1.79.0-nightly
LLVM version: 18.1.2
Error output
error: non-item in item list
--> ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:2:15
|
1 | trait UnwrapItemsExt<'a, > {
| - item list starts here
2 | type Iter;=
| ^ non-item starts here
3 | }
| - item list ends here
error[E0407]: method `unwrap_items` is not a member of trait `UnwrapItemsExt`
--> ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:13:5
|
13 | / fn unwrap_items(self) -> Self::Iter {
14 | | MyStruct::<C> {}
15 | | }
| |_____^ not a member of trait `UnwrapItemsExt`
error[E0658]: `impl Trait` in associated types is unstable
--> ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:12:17
|
12 | type Iter = impl MyTrait<'a, C>;
| ^^^^^^^^^^^^^^^^^^^
|
= note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
= help: add `#![feature(impl_trait_in_assoc_type)]` to the crate attributes to enable
= note: this compiler was built on 2024-04-04; consider upgrading it if it is out of date
error[E0107]: trait takes 0 generic arguments but 1 generic argument was supplied
--> ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:11:29
|
11 | impl<'a, I, const C: usize> UnwrapItemsExt<'a, C> for I {
| ^^^^^^^^^^^^^^ expected 0 generic arguments
|
note: trait defined here, with 0 generic parameters
--> ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:1:7
|
1 | trait UnwrapItemsExt<'a, > {
| ^^^^^^^^^^^^^^
error[E0207]: the const parameter `C` is not constrained by the impl trait, self type, or predicates
--> ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:11:13
|
11 | impl<'a, I, const C: usize> UnwrapItemsExt<'a, C> for I {
| ^^^^^^^^^^^^^^ unconstrained const parameter
|
= note: expressions using a const parameter must map each value to a distinct output value
= note: proving the result of expressions other than the parameter are unique is not supported
Backtrace
thread 'rustc' panicked at compiler/rustc_borrowck/src/type_check/relate_tys.rs:441:9:
unexpected inference var ?0c: usize
stack backtrace:
0: 0x103492797 - std::backtrace::Backtrace::create::h72d3f6df5a38e04e
1: 0x1034926e5 - std::backtrace::Backtrace::force_capture::hfb9db3afdd7ed5a0
2: 0x10c041cfb - std[be7050f24520aea4]::panicking::update_hook::<alloc[2a9bcbeb98b329c5]::boxed::Box<rustc_driver_impl[8bfb916414656838]::install_ice_hook::{closure#0}>>::{closure#0}
3: 0x1034ac564 - std::panicking::rust_panic_with_hook::hd67e9f54f7f40054
4: 0x1034abea4 - std::panicking::begin_panic_handler::{{closure}}::h8d3afd8e6d4ebb5c
5: 0x1034a9379 - std::sys_common::backtrace::__rust_end_short_backtrace::h18e72b50cfea1b84
6: 0x1034abbd6 - _rust_begin_unwind
7: 0x103511355 - core::panicking::panic_fmt::hdd6020c145d16e40
8: 0x10bb697b4 - <rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating as rustc_middle[1ad5f3b6432680d2]::ty::relate::TypeRelation>::consts
9: 0x10bbad2fc - <rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating as rustc_middle[1ad5f3b6432680d2]::ty::relate::TypeRelation>::relate_with_variance::<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>
10: 0x10ba39b3d - <core[95a55440902af925]::iter::adapters::GenericShunt<core[95a55440902af925]::iter::adapters::map::Map<core[95a55440902af925]::iter::adapters::enumerate::Enumerate<core[95a55440902af925]::iter::adapters::zip::Zip<core[95a55440902af925]::iter::adapters::copied::Copied<core[95a55440902af925]::slice::iter::Iter<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>, core[95a55440902af925]::iter::adapters::copied::Copied<core[95a55440902af925]::slice::iter::Iter<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>>>, rustc_middle[1ad5f3b6432680d2]::ty::relate::relate_args_with_variances<rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating>::{closure#0}>, core[95a55440902af925]::result::Result<core[95a55440902af925]::convert::Infallible, rustc_middle[1ad5f3b6432680d2]::ty::error::TypeError>> as core[95a55440902af925]::iter::traits::iterator::Iterator>::try_fold::<(), core[95a55440902af925]::iter::traits::iterator::Iterator::try_for_each::call<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg, core[95a55440902af925]::ops::control_flow::ControlFlow<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>, core[95a55440902af925]::ops::control_flow::ControlFlow<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>::Break>::{closure#0}, core[95a55440902af925]::ops::control_flow::ControlFlow<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>
11: 0x10ba52d29 - <core[95a55440902af925]::result::Result<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg, rustc_middle[1ad5f3b6432680d2]::ty::error::TypeError> as rustc_type_ir[39b748d160e12b68]::interner::CollectAndApply<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg, &rustc_middle[1ad5f3b6432680d2]::ty::list::List<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>>::collect_and_apply::<core[95a55440902af925]::iter::adapters::map::Map<core[95a55440902af925]::iter::adapters::enumerate::Enumerate<core[95a55440902af925]::iter::adapters::zip::Zip<core[95a55440902af925]::iter::adapters::copied::Copied<core[95a55440902af925]::slice::iter::Iter<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>, core[95a55440902af925]::iter::adapters::copied::Copied<core[95a55440902af925]::slice::iter::Iter<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>>>, rustc_middle[1ad5f3b6432680d2]::ty::relate::relate_args_with_variances<rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating>::{closure#0}>, <rustc_middle[1ad5f3b6432680d2]::ty::context::TyCtxt>::mk_args_from_iter<core[95a55440902af925]::iter::adapters::map::Map<core[95a55440902af925]::iter::adapters::enumerate::Enumerate<core[95a55440902af925]::iter::adapters::zip::Zip<core[95a55440902af925]::iter::adapters::copied::Copied<core[95a55440902af925]::slice::iter::Iter<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>, core[95a55440902af925]::iter::adapters::copied::Copied<core[95a55440902af925]::slice::iter::Iter<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg>>>>, rustc_middle[1ad5f3b6432680d2]::ty::relate::relate_args_with_variances<rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating>::{closure#0}>, core[95a55440902af925]::result::Result<rustc_middle[1ad5f3b6432680d2]::ty::generic_args::GenericArg, rustc_middle[1ad5f3b6432680d2]::ty::error::TypeError>>::{closure#0}>
12: 0x10ba3b842 - <rustc_middle[1ad5f3b6432680d2]::ty::sty::AliasTy as rustc_middle[1ad5f3b6432680d2]::ty::relate::Relate>::relate::<rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating>
13: 0x10b9b7394 - <rustc_infer[243809f999046ed9]::infer::InferCtxt>::super_combine_tys::<rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating>
14: 0x10bbad962 - <rustc_borrowck[b118bb05d7b0041d]::type_check::relate_tys::NllTypeRelating as rustc_middle[1ad5f3b6432680d2]::ty::relate::TypeRelation>::tys
15: 0x10bbac7c4 - <rustc_borrowck[b118bb05d7b0041d]::type_check::TypeChecker>::relate_types
16: 0x10bbac532 - <rustc_borrowck[b118bb05d7b0041d]::type_check::TypeChecker>::equate_normalized_input_or_output
17: 0x10bb6deb1 - rustc_borrowck[b118bb05d7b0041d]::type_check::type_check
18: 0x10bb3f190 - rustc_borrowck[b118bb05d7b0041d]::nll::compute_regions
19: 0x10bbbc428 - rustc_borrowck[b118bb05d7b0041d]::do_mir_borrowck
20: 0x10bb81df2 - rustc_borrowck[b118bb05d7b0041d]::mir_borrowck
21: 0x10d46963a - rustc_query_impl[90888abca995a36a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[90888abca995a36a]::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>
22: 0x10d2eeccc - rustc_query_system[86526c3e26299dee]::query::plumbing::try_execute_query::<rustc_query_impl[90888abca995a36a]::DynamicConfig<rustc_query_system[86526c3e26299dee]::query::caches::VecCache<rustc_hir[36aeddbba5c0fbdc]::hir_id::OwnerId, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[90888abca995a36a]::plumbing::QueryCtxt, false>
23: 0x10d49198b - rustc_query_impl[90888abca995a36a]::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
24: 0x10c24cf78 - rustc_middle[1ad5f3b6432680d2]::query::plumbing::query_get_at::<rustc_query_system[86526c3e26299dee]::query::caches::VecCache<rustc_hir[36aeddbba5c0fbdc]::hir_id::OwnerId, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>>
25: 0x10c3be570 - <rustc_hir_analysis[9a5a8480ab2c754]::collect::type_of::opaque::TaitConstraintLocator>::check
26: 0x10c358e4a - rustc_hir_analysis[9a5a8480ab2c754]::collect::type_of::type_of_opaque
27: 0x10d469eaa - rustc_query_impl[90888abca995a36a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[90888abca995a36a]::query_impl::type_of_opaque::dynamic_query::{closure#2}::{closure#0}, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>
28: 0x10d24bb93 - rustc_query_system[86526c3e26299dee]::query::plumbing::try_execute_query::<rustc_query_impl[90888abca995a36a]::DynamicConfig<rustc_query_system[86526c3e26299dee]::query::caches::DefIdCache<rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[90888abca995a36a]::plumbing::QueryCtxt, false>
29: 0x10d476ca9 - rustc_query_impl[90888abca995a36a]::query_impl::type_of_opaque::get_query_non_incr::__rust_end_short_backtrace
30: 0x10c24c52e - rustc_middle[1ad5f3b6432680d2]::query::plumbing::query_get_at::<rustc_query_system[86526c3e26299dee]::query::caches::DefIdCache<rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>>
31: 0x10c357bed - rustc_hir_analysis[9a5a8480ab2c754]::collect::type_of::type_of
32: 0x10d46da66 - rustc_query_impl[90888abca995a36a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[90888abca995a36a]::query_impl::type_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>
33: 0x10d24bb93 - rustc_query_system[86526c3e26299dee]::query::plumbing::try_execute_query::<rustc_query_impl[90888abca995a36a]::DynamicConfig<rustc_query_system[86526c3e26299dee]::query::caches::DefIdCache<rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[90888abca995a36a]::plumbing::QueryCtxt, false>
34: 0x10d4768f9 - rustc_query_impl[90888abca995a36a]::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace
35: 0x10c24c52e - rustc_middle[1ad5f3b6432680d2]::query::plumbing::query_get_at::<rustc_query_system[86526c3e26299dee]::query::caches::DefIdCache<rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 8usize]>>>
36: 0x10c2c6352 - rustc_hir_analysis[9a5a8480ab2c754]::check::check::check_item_type
37: 0x10c2fdca9 - rustc_hir_analysis[9a5a8480ab2c754]::check::wfcheck::check_well_formed
38: 0x10d46ad6a - rustc_query_impl[90888abca995a36a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[90888abca995a36a]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 1usize]>>
39: 0x10d2ec8fc - rustc_query_system[86526c3e26299dee]::query::plumbing::try_execute_query::<rustc_query_impl[90888abca995a36a]::DynamicConfig<rustc_query_system[86526c3e26299dee]::query::caches::VecCache<rustc_hir[36aeddbba5c0fbdc]::hir_id::OwnerId, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[90888abca995a36a]::plumbing::QueryCtxt, false>
40: 0x10d4b17e0 - rustc_query_impl[90888abca995a36a]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
41: 0x10c24d527 - rustc_middle[1ad5f3b6432680d2]::query::plumbing::query_ensure_error_guaranteed::<rustc_query_system[86526c3e26299dee]::query::caches::VecCache<rustc_hir[36aeddbba5c0fbdc]::hir_id::OwnerId, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 1usize]>>, ()>
42: 0x10c30b9b1 - rustc_hir_analysis[9a5a8480ab2c754]::check::wfcheck::check_mod_type_wf
43: 0x10d46ad5a - rustc_query_impl[90888abca995a36a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[90888abca995a36a]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 1usize]>>
44: 0x10d2a2b91 - rustc_query_system[86526c3e26299dee]::query::plumbing::try_execute_query::<rustc_query_impl[90888abca995a36a]::DynamicConfig<rustc_query_system[86526c3e26299dee]::query::caches::DefaultCache<rustc_span[3abddbc5b7091f5a]::def_id::LocalModDefId, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[90888abca995a36a]::plumbing::QueryCtxt, false>
45: 0x10d48fc80 - rustc_query_impl[90888abca995a36a]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
46: 0x10c383a6c - rustc_hir_analysis[9a5a8480ab2c754]::check_crate
47: 0x10c7eb1e0 - rustc_interface[230cab390baedc2]::passes::analysis
48: 0x10d46da7a - rustc_query_impl[90888abca995a36a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[90888abca995a36a]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 1usize]>>
49: 0x10d256efe - rustc_query_system[86526c3e26299dee]::query::plumbing::try_execute_query::<rustc_query_impl[90888abca995a36a]::DynamicConfig<rustc_query_system[86526c3e26299dee]::query::caches::SingleCache<rustc_middle[1ad5f3b6432680d2]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[90888abca995a36a]::plumbing::QueryCtxt, false>
50: 0x10d477e47 - rustc_query_impl[90888abca995a36a]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
51: 0x10bfed5a7 - <rustc_interface[230cab390baedc2]::queries::QueryResult<&rustc_middle[1ad5f3b6432680d2]::ty::context::GlobalCtxt>>::enter::<core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>, rustc_driver_impl[8bfb916414656838]::run_compiler::{closure#0}::{closure#1}::{closure#3}>
52: 0x10c0401af - rustc_interface[230cab390baedc2]::interface::run_compiler::<core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>, rustc_driver_impl[8bfb916414656838]::run_compiler::{closure#0}>::{closure#0}
53: 0x10c0375ad - std[be7050f24520aea4]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[230cab390baedc2]::util::run_in_thread_with_globals<rustc_interface[230cab390baedc2]::util::run_in_thread_pool_with_globals<rustc_interface[230cab390baedc2]::interface::run_compiler<core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>, rustc_driver_impl[8bfb916414656838]::run_compiler::{closure#0}>::{closure#0}, core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>>::{closure#0}, core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>>
54: 0x10c04998f - <<std[be7050f24520aea4]::thread::Builder>::spawn_unchecked_<rustc_interface[230cab390baedc2]::util::run_in_thread_with_globals<rustc_interface[230cab390baedc2]::util::run_in_thread_pool_with_globals<rustc_interface[230cab390baedc2]::interface::run_compiler<core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>, rustc_driver_impl[8bfb916414656838]::run_compiler::{closure#0}>::{closure#0}, core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>>::{closure#0}, core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95a55440902af925]::result::Result<(), rustc_span[3abddbc5b7091f5a]::ErrorGuaranteed>>::{closure#1} as core[95a55440902af925]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
55: 0x1034b574b - std::sys::pal::unix::thread::Thread::new::thread_start::he5f939c93f920ed5
56: 0x7ff818270202 - __pthread_start
rustc version: 1.79.0-nightly (385fa9d84 2024-04-04)
platform: x86_64-apple-darwin
query stack during panic:
#0 [mir_borrowck] borrow-checking `<impl at ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:11:1: 11:56>::unwrap_items`
#1 [type_of_opaque] computing type of opaque `<impl at ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:11:1: 11:56>::Iter::{opaque#0}`
#2 [type_of] computing type of `<impl at ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:11:1: 11:56>::Iter::{opaque#0}`
#3 [check_well_formed] checking that `<impl at ./D6BD4FB55462A1C16D63A187D670720C36D17D621F27BB3730F935512411FC53.rs:11:1: 11:56>::Iter::{opaque#0}` is well-formed
#4 [check_mod_type_wf] checking that types are well-formed in top-level module
#5 [analysis] running analysis passes on this crate
end of query stack