de-non_const Iterator trait methods

[Lars-Schumann]

#92476

constifying Iterators methods that don't immediately or transitively need const closures or ugly hacks.

[rustbot]

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[oli-obk]

Maybe we should figure that one out first 😅

[Lars-Schumann]

As far as const-hacks go, this is very tame, and I didn't want to make this pr too big by constifying the Range Iterator impl as well (if that's even possible right now)

[oli-obk]

yea, def don't do range iterators this in this one, I was wondering if we'd just delay on touching this one. But it is tame, and I do worry that by not doing progress here we end up in a deadlock somewhere with other iterator constifications.

[oli-obk]

@bors r+ rollup

[rust-bors]

📌 Commit 2960e3a has been approved by oli-obk

It is now in the queue for this repository.

[Zalathar]

• Investigating Rollup of 11 pull requests #153767 (comment)

@bors try jobs=x86_64-rust-for-linux

[Zalathar]

On closer inspection the error mentions Iterator, so I’ll assume that this PR Is the most likely cause.

@bors r-

[rust-bors]

This pull request was unapproved.

This PR was contained in a rollup (#153767), which was unapproved.

[JonathanBrouwer]

@bors r-
@bors try jobs=x86_64-rust-for-linux
#153767 (comment)

[rust-bors]

💔 Test for 4b830c9 failed: CI. Failed job:

• try - x86_64-rust-for-linux (web logs, enhanced plaintext logs)

[rust-log-analyzer]

The job x86_64-rust-for-linux failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

  RUSTDOC H rust/quote/lib.rs
  RUSTDOC H rust/syn/lib.rs
  RUSTDOC H rust/macros/lib.rs
  RUSTDOC H rust/pin-init/src/lib.rs
##[error]error: internal compiler error: compiler/rustc_middle/src/ty/typeck_results.rs:590:9: node HirId(DefId(0:9602 ~ core[e2d3]::iter::traits::iterator::Iterator::advance_by::{impl#0}).9) (type `I::Item`) cannot be placed in TypeckResults with hir_owner DefId(0:9599 ~ core[e2d3]::iter::traits::iterator::Iterator::advance_by)


thread 'rustc' (57083) panicked at compiler/rustc_middle/src/ty/typeck_results.rs:590:9:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   3: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   4: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   5: rustc_middle::util::bug::bug_fmt
   6: rustc_middle::ty::typeck_results::invalid_hir_id_for_typeck_results::{closure#0}
   7: rustc_middle::ty::context::tls::with::<rustc_middle::ty::typeck_results::invalid_hir_id_for_typeck_results::{closure#0}, !>::{closure#0}
   8: rustc_middle::ty::context::tls::with_context::<rustc_middle::ty::context::tls::with<rustc_middle::ty::typeck_results::invalid_hir_id_for_typeck_results::{closure#0}, !>::{closure#0}, !>::{closure#0}
   9: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_context<rustc_middle::ty::context::tls::with<rustc_middle::ty::typeck_results::invalid_hir_id_for_typeck_results::{closure#0}, !>::{closure#0}, !>::{closure#0}, !>
  10: rustc_middle::ty::context::tls::with::<rustc_middle::ty::typeck_results::invalid_hir_id_for_typeck_results::{closure#0}, !>
  11: rustc_middle::ty::typeck_results::invalid_hir_id_for_typeck_results
  12: <rustc_middle::ty::typeck_results::TypeckResults>::qpath_res
  13: <rustdoc::html::render::span_map::SpanMapVisitor as rustc_hir::intravisit::Visitor>::visit_qpath
  14: rustc_hir::intravisit::walk_where_predicate::<rustdoc::html::render::span_map::SpanMapVisitor>
  15: rustc_hir::intravisit::walk_generics::<rustdoc::html::render::span_map::SpanMapVisitor>
  16: rustc_hir::intravisit::walk_item::<rustdoc::html::render::span_map::SpanMapVisitor>
  17: rustc_hir::intravisit::walk_stmt::<rustdoc::html::render::span_map::SpanMapVisitor>
  18: rustc_hir::intravisit::walk_expr::<rustdoc::html::render::span_map::SpanMapVisitor>
  19: rustc_hir::intravisit::walk_trait_item::<rustdoc::html::render::span_map::SpanMapVisitor>
  20: rustc_hir::intravisit::walk_item::<rustdoc::html::render::span_map::SpanMapVisitor>
  21: rustc_hir::intravisit::walk_mod::<rustdoc::html::render::span_map::SpanMapVisitor>
  22: rustc_hir::intravisit::walk_mod::<rustdoc::html::render::span_map::SpanMapVisitor>
  23: rustc_hir::intravisit::walk_mod::<rustdoc::html::render::span_map::SpanMapVisitor>
  24: rustc_hir::intravisit::walk_mod::<rustdoc::html::render::span_map::SpanMapVisitor>
  25: <rustdoc::html::render::context::Context>::init
  26: rustdoc::formats::renderer::run_format::<rustdoc::html::render::context::Context, rustdoc::main_args::{closure#2}::{closure#0}::{closure#1}::{closure#0}>
  27: <std::thread::local::LocalKey<core::cell::Cell<*const ()>>>::with::<rustc_middle::ty::context::tls::enter_context<<rustc_middle::ty::context::GlobalCtxt>::enter<rustc_interface::passes::create_and_enter_global_ctxt<(), rustdoc::main_args::{closure#2}::{closure#0}>::{closure#2}, ()>::{closure#1}, ()>::{closure#0}, ()>
  28: rustc_interface::passes::create_and_enter_global_ctxt::<(), rustdoc::main_args::{closure#2}::{closure#0}>
  29: rustc_interface::interface::run_compiler::<(), rustdoc::main_args::{closure#2}>::{closure#1}
  30: rustc_span::create_session_globals_then::<(), rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustdoc::main_args::{closure#2}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md

note: please make sure that you have updated to the latest nightly

note: please attach the file at `/checkout/obj/rfl/linux/rustc-ice-2026-03-12T12_24_21-57075.txt` to your bug report

note: rustc 1.96.0-nightly (4b830c956 2026-03-12) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z binary_dep_depinfo=y -C panic=abort -C embed-bitcode=n -C lto=n -C force-unwind-tables=n -C codegen-units=1 -C symbol-mangling-version=v0 -C relocation-model=static -Z function-sections=n -C target-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2 -Z cf-protection=branch -C jump-tables=n -C target-cpu=x86-64 -Z tune-cpu=generic -C no-redzone=y -C code-model=kernel -Z function-return=thunk-extern -Z patchable-function-entry=16,16 -C opt-level=2 -C debug-assertions=n -C overflow-checks=y -Z unstable-options -C unsafe-allow-abi-mismatch=fixed-x18

query stack during panic:
end of query stack
error: aborting due to 1 previous error

make[2]: *** [rust/Makefile:200: rustdoc-core] Error 101
make[1]: *** [/checkout/obj/rfl/linux/Makefile:1858: rustdoc] Error 2
make: *** [Makefile:248: __sub-make] Error 2
make: Leaving directory '/checkout/obj/rfl/linux'
  local time: Thu Mar 12 12:24:21 UTC 2026
  network time: Thu, 12 Mar 2026 12:24:21 GMT
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[rust-bors]

☔ The latest upstream changes (presumably #154535) made this pull request unmergeable. Please resolve the merge conflicts.