Description
openedon Jul 7, 2019
#![feature(const_generics)]
use std::fmt;
struct Builder<const N: usize> {
items: [&'static str; N],
}
fn new_builder() -> Builder<{0}> {
return Builder{items: []};
}
impl<const N: usize> Builder<{ N }> {
fn append(self, value: &'static str) -> Builder<{ N + 1 }> {
let mut new_items = [""; N + 1];
new_items[..N].copy_from_slice(self.items);
new_items[N] = value;
return Builder { items: new_items };
}
fn build(self) -> Final<{ N }> {
return Final { items: self.items };
}
}
struct Final<const N: usize> {
items: [&'static str; N],
}
impl<const N: usize> fmt::Debug for Final<{ N }> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("Final")
.field("items", &&self.items[..])
.finish()
}
}
fn main() {
let f = new_builder()
.append("abc")
.append("def")
.append("ghi")
.build();
println!("f={:?}", f);
} Compiling playground v0.0.1 (/playground)
warning: the feature `const_generics` is incomplete and may cause the compiler to crash
--> src/main.rs:1:12
|
1 | #![feature(const_generics)]
| ^^^^^^^^^^^^^^
thread 'rustc' panicked at 'index out of bounds: the len is 1 but the index is 1', /rustc/481068a707679257e2a738b40987246e0420e787/src/libcore/slice/mod.rs:2681:10
stack backtrace:
0: backtrace::backtrace::libunwind::trace
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/libunwind.rs:88
1: backtrace::backtrace::trace_unsynchronized
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/mod.rs:66
2: std::sys_common::backtrace::_print
at src/libstd/sys_common/backtrace.rs:47
3: std::sys_common::backtrace::print
at src/libstd/sys_common/backtrace.rs:36
4: std::panicking::default_hook::{{closure}}
at src/libstd/panicking.rs:200
5: std::panicking::default_hook
at src/libstd/panicking.rs:214
6: rustc::util::common::panic_hook
7: std::panicking::rust_panic_with_hook
at src/libstd/panicking.rs:481
8: std::panicking::continue_panic_fmt
at src/libstd/panicking.rs:384
9: rust_begin_unwind
at src/libstd/panicking.rs:311
10: core::panicking::panic_fmt
at src/libcore/panicking.rs:85
11: core::panicking::panic_bounds_check
at src/libcore/panicking.rs:61
12: rustc_mir::borrow_check::nll::type_check::type_check
13: rustc_mir::borrow_check::nll::compute_regions
14: rustc_mir::borrow_check::do_mir_borrowck
15: rustc::ty::context::GlobalCtxt::enter_local
16: rustc_mir::borrow_check::mir_borrowck
17: rustc::ty::query::__query_compute::mir_borrowck
18: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::mir_borrowck>::compute
19: rustc::dep_graph::graph::DepGraph::with_task_impl
20: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
21: rustc::ty::<impl rustc::ty::context::TyCtxt>::par_body_owners
22: rustc::util::common::time
23: rustc_interface::passes::analysis
24: rustc::ty::query::__query_compute::analysis
25: rustc::dep_graph::graph::DepGraph::with_task_impl
26: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
27: rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}}
28: rustc_interface::passes::create_global_ctxt::{{closure}}
29: rustc_interface::interface::run_compiler_in_existing_thread_pool
30: std::thread::local::LocalKey<T>::with
31: scoped_tls::ScopedKey<T>::set
32: syntax::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
query stack during panic:
#0 [mir_borrowck] processing `Builder::<N>::append`
#1 [analysis] running analysis passes on this crate
end of query stack
error: internal compiler error: cat_expr Errd
--> src/main.rs:14:64
|
14 | fn append(self, value: &'static str) -> Builder<{ N + 1 }> {
| ________________________________________________________________^
15 | | let mut new_items = [""; N + 1];
16 | | new_items[..N].copy_from_slice(self.items);
17 | | new_items[N] = value;
18 | | return Builder { items: new_items };
19 | | }
| |_____^
error: internal compiler error: cat_expr Errd
--> src/main.rs:15:29
|
15 | let mut new_items = [""; N + 1];
| ^^^^^^^^^^^
error: internal compiler error: cat_expr Errd
--> src/main.rs:16:9
|
16 | new_items[..N].copy_from_slice(self.items);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: internal compiler error: cat_expr Errd
--> src/main.rs:16:9
|
16 | new_items[..N].copy_from_slice(self.items);
| ^^^^^^^^^^^^^^
error: internal compiler error: cat_expr Errd
--> src/main.rs:16:9
|
16 | new_items[..N].copy_from_slice(self.items);
| ^^^^^^^^^
error: internal compiler error: cat_expr Errd
--> src/main.rs:17:9
|
17 | new_items[N] = value;
| ^^^^^^^^^^^^^^^^^^^^
error: internal compiler error: cat_expr Errd
--> src/main.rs:17:9
|
17 | new_items[N] = value;
| ^^^^^^^^^^^^
error: internal compiler error: cat_expr Errd
--> src/main.rs:17:9
|
17 | new_items[N] = value;
| ^^^^^^^^^
error: internal compiler error: cat_expr Errd
--> src/main.rs:18:33
|
18 | return Builder { items: new_items };
| ^^^^^^^^^
error: internal compiler error: no type-dependent def for method call
--> src/main.rs:16:9
|
16 | new_items[..N].copy_from_slice(self.items);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: internal compiler error: QualifyAndPromoteConstants: MIR had errors
--> src/main.rs:14:5
|
14 | / fn append(self, value: &'static str) -> Builder<{ N + 1 }> {
15 | | let mut new_items = [""; N + 1];
16 | | new_items[..N].copy_from_slice(self.items);
17 | | new_items[N] = value;
18 | | return Builder { items: new_items };
19 | | }
| |_____^
error: internal compiler error: broken MIR in DefId(0:22 ~ playground[a9b4]::{{impl}}[0]::append[0]) ("return type"): bad type [type error]
--> src/main.rs:14:5
|
14 | / fn append(self, value: &'static str) -> Builder<{ N + 1 }> {
15 | | let mut new_items = [""; N + 1];
16 | | new_items[..N].copy_from_slice(self.items);
17 | | new_items[N] = value;
18 | | return Builder { items: new_items };
19 | | }
| |_____^
error: internal compiler error: broken MIR in DefId(0:22 ~ playground[a9b4]::{{impl}}[0]::append[0]) (LocalDecl { mutability: Mut, is_user_variable: None, internal: false, is_block_tail: None, ty: [type error], user_ty: UserTypeProjections { contents: [] }, name: None, source_info: SourceInfo { span: src/main.rs:14:5: 19:6, scope: scope[0] }, visibility_scope: scope[0] }): bad type [type error]
--> src/main.rs:14:5
|
14 | / fn append(self, value: &'static str) -> Builder<{ N + 1 }> {
15 | | let mut new_items = [""; N + 1];
16 | | new_items[..N].copy_from_slice(self.items);
17 | | new_items[N] = value;
18 | | return Builder { items: new_items };
19 | | }
| |_____^
thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', src/librustc_errors/lib.rs:366:17
stack backtrace:
0: 0x7f2a9f73e24b - backtrace::backtrace::libunwind::trace::hda4e121c515bf458
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/libunwind.rs:88
1: 0x7f2a9f73e24b - backtrace::backtrace::trace_unsynchronized::h0a71c953a4742195
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/mod.rs:66
2: 0x7f2a9f73e24b - std::sys_common::backtrace::_print::hf4a62558314f5307
at src/libstd/sys_common/backtrace.rs:47
3: 0x7f2a9f73e24b - std::sys_common::backtrace::print::hcb7a471013853997
at src/libstd/sys_common/backtrace.rs:36
4: 0x7f2a9f73e24b - std::panicking::default_hook::{{closure}}::ha0ea642565fdae2f
at src/libstd/panicking.rs:200
5: 0x7f2a9f73df27 - std::panicking::default_hook::h0f057f6c7c516eb6
at src/libstd/panicking.rs:214
6: 0x7f2a9cde32c1 - rustc::util::common::panic_hook::hc3d6a9f610b367e7
7: 0x7f2a9f73eaa9 - std::panicking::rust_panic_with_hook::hc77fb9874fa29555
at src/libstd/panicking.rs:481
8: 0x7f2a9ba562a5 - std::panicking::begin_panic::h6e376c592b6253f0
9: 0x7f2a9ba79dc5 - <rustc_errors::Handler as core::ops::drop::Drop>::drop::h34bba684e8175cc7
10: 0x7f2a9fa54b82 - core::ptr::real_drop_in_place::hb2f5bc0c04a6a718
11: 0x7f2a9fa59e94 - <alloc::rc::Rc<T> as core::ops::drop::Drop>::drop::hbcc6465daa24608a
12: 0x7f2a9fa270ac - core::ptr::real_drop_in_place::h5e74c5df24af64f3
13: 0x7f2a9fa24058 - rustc_interface::interface::run_compiler_in_existing_thread_pool::hfa8966a3f2d428a3
14: 0x7f2a9fa380c2 - std::thread::local::LocalKey<T>::with::ha697a453d1de3d8a
15: 0x7f2a9fa4b071 - scoped_tls::ScopedKey<T>::set::h50b61de3f9f457ff
16: 0x7f2a9fa62954 - syntax::with_globals::h2642fa717df1d186
17: 0x7f2a9fa8ca0d - std::sys_common::backtrace::__rust_begin_short_backtrace::ha67256aa038100bc
18: 0x7f2a9f74f50a - __rust_maybe_catch_panic
at src/libpanic_unwind/lib.rs:82
19: 0x7f2a9fa0a9f9 - core::ops::function::FnOnce::call_once{{vtable.shim}}::h187e5c932baee631
20: 0x7f2a9f721ecf - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h4b1f48c87819f1d7
at /rustc/481068a707679257e2a738b40987246e0420e787/src/liballoc/boxed.rs:766
21: 0x7f2a9f74e1f0 - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h982c5ef9aacde87b
at /rustc/481068a707679257e2a738b40987246e0420e787/src/liballoc/boxed.rs:766
22: 0x7f2a9f74e1f0 - std::sys_common::thread::start_thread::h961b6807ee2d2f95
at src/libstd/sys_common/thread.rs:13
23: 0x7f2a9f74e1f0 - std::sys::unix::thread::Thread::new::thread_start::h166a70c782ebeb55
at src/libstd/sys/unix/thread.rs:79
24: 0x7f2a9f4be6db - start_thread
25: 0x7f2a9eddb88f - __clone
26: 0x0 - <unknown>
query stack during panic:
end of query stack
thread panicked while panicking. aborting.
error: Could not compile `playground`.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Metadata
Assignees
Labels
Area: const generics (parameters and arguments)Category: This is a bug.`#![feature(const_generics)]`Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️Relevant to the compiler team, which will review and decide on the PR/issue.ICE tracked in rust-lang/glacier.This issue requires a nightly compiler in some way.