Closed
Description
This is on MacOS X with rustc 1.12.0-nightly (1deb02ea6 2016-08-12).
This program:
#![feature(conservative_impl_trait)]
fn func<'a, T>(a: &'a [T]) -> impl Iterator<Item=&'a T> {
a.iter().map(|a| a*a)
}
fn main() {
let a = (0..30).collect::<Vec<_>>();
for k in func(&a) {
println!("{}", k);
}
}crashes with
Compiling blub v0.1.0 (file:///private/tmp/blub)
error[E0369]: binary operation `*` cannot be applied to type `&T`
--> src/main.rs:4:22
|
4 | a.iter().map(|a| a*a)
| ^
|
note: an implementation of `std::ops::Mul` might be missing for `&T`
--> src/main.rs:4:22
|
4 | a.iter().map(|a| a*a)
| ^
error: internal compiler error: ../src/librustc_typeck/check/writeback.rs:343: invalid region in impl Trait: ReEmpty
--> src/main.rs:3:31
|
3 | fn func<'a, T>(a: &'a [T]) -> impl Iterator<Item=&'a T> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box<Any>', ../src/librustc_errors/lib.rs:580
stack backtrace:
1: 0x10b78343e - std::sys::backtrace::tracing::imp::write::h29f5fdb9fc0a7395
2: 0x10b79258f - std::panicking::default_hook::_{{closure}}::h17d8437f66223ab1
3: 0x10b790a1d - std::panicking::default_hook::hbbe7fa36a995aca0
4: 0x10b791136 - std::panicking::rust_panic_with_hook::h105c3d42fcd2fb5e
5: 0x106dc932b - std::panicking::begin_panic::hccc513334ab977d2
6: 0x106f24c7d - rustc::session::opt_span_bug_fmt::_{{closure}}::h62b0957667555cfe
7: 0x106df9959 - rustc::session::span_bug_fmt::hcdfbe9cf944f6fc3
8: 0x106f1f9f9 - rustc_typeck::check::writeback::WritebackCx::visit_anon_types::_{{closure}}::hc59c3ae4d9a65396
9: 0x107f3a55d - _<rustc..ty..fold..RegionFolder<'a, 'gcx, 'tcx> as rustc..ty..fold..TypeFolder<'gcx, 'tcx>>::fold_region::hf546bdf998324773
10: 0x106de1948 - rustc::ty::fold::TypeFolder::fold_substs::h55fbad8fa7647f08
11: 0x106de2922 - rustc::ty::fold::TypeFolder::fold_ty::hb0362f5378b07a40
12: 0x106de1b99 - rustc::ty::fold::TypeFolder::fold_substs::h55fbad8fa7647f08
13: 0x106de2922 - rustc::ty::fold::TypeFolder::fold_ty::hb0362f5378b07a40
14: 0x106e26e95 - rustc_typeck::check::writeback::_<impl rustc_typeck..check..FnCtxt<'a, 'gcx, 'tcx>>::resolve_type_vars_in_fn::h2c631aecefe427eb
15: 0x106e8e2b8 - rustc_typeck::check::check_bare_fn::h705fb24e3f39423b
16: 0x106e92232 - rustc_typeck::check::check_item_body::h26c5d995a8cf2591
17: 0x106e8af75 - rustc_typeck::check::check_item_bodies::h879e0600ff9f7c52
18: 0x106f09998 - rustc_typeck::check_crate::h3586447e34ddb139
19: 0x106bfb53a - rustc_driver::driver::phase_3_run_analysis_passes::_{{closure}}::h7f2cec505064b4bf
20: 0x106b62372 - rustc::ty::context::TyCtxt::create_and_enter::he5dca3f2a7a0810a
21: 0x106bc426f - rustc_driver::driver::compile_input::hb4cc34cf85dc1edf
22: 0x106bec440 - rustc_driver::run_compiler::h50f95674bd902ab5
23: 0x106b3794e - std::panicking::try::call::h31fc30b58c55d6c3
24: 0x10b79940a - __rust_maybe_catch_panic
25: 0x106b51033 - _<F as alloc..boxed..FnBox<A>>::call_box::h24f3eb0b42327962
26: 0x10b78f7d5 - std::sys::thread::Thread::new::thread_start::h8f3bd45211e9f5ea
27: 0x7fff82f2599c - _pthread_body
28: 0x7fff82f25919 - _pthread_start
error: Could not compile `blub`.
To learn more, run the command again with --verbose.