Niels Lohmann 09d41a894b Re-enable bugprone-use-after-move/hicpp-invalid-access-moved ...

These two checks (and portability-template-virtual-member-function)
were disabled in #4489 (November 2024) "only removed to get the CI
going". portability-template-virtual-member-function is a separate,
still-open cleanup (#5725 item 3 on its own branch) and stays
disabled here; this commit only re-enables the move/forward checks
and cleans up what they flag on this branch.

The move constructor (json.hpp) already casts to the base type
instead of forwarding the whole object (#5724 item 9), so it no
longer trips either check. The at(KeyType&&) double-forward this
check used to flag was reduced to a single forward with the
now-unforwarded reuse annotated by a NOLINTNEXTLINE in #5724 item 3's
object_at() helper (clang-tidy 22 still flags that reuse even after a
single forward; see that commit's message). What is left here:

- from_json_inplace_array_impl(), from_json_tuple_impl_base() and the
  std::pair overload of from_json_tuple_impl() forwarded j into every
  j.at(...) call in a pack expansion or a pair of calls. at() has no
  ref-qualified overloads, so the forward was a no-op; call j.at(...)
  directly.
- container_input_adapter_factory::create() forwards container twice
  on purpose, into begin() and end(), so both see the same value
  category and produce matching iterator types. Annotate it with
  NOLINTNEXTLINE and a comment instead of changing it.
- unit-class_parser.cpp's "move constructor resets the moved-from
  value to npos" test still pointed at the pre-static_cast move
  constructor by line number and mentioned the cppcheck-suppress
  annotation that #5724 item 9 already removed; update the comment.

No behavior change anywhere in include/. Verified with clang-tidy 22.1.8
(Docker silkeh/clang:22, --platform linux/amd64) against a TU including
json.hpp with the repo's .clang-tidy: bugprone-use-after-move and
hicpp-invalid-access-moved report nothing unsuppressed.

Overlaps #5737 (open PR for the rest of #5725 item 3: the
from_json.hpp/input_adapters.hpp cleanup above, and
portability-template-virtual-member-function), which currently keeps
both checks disabled pending this move-constructor change; whichever
of this commit and that PR lands second will need a small rebase of
.clang-tidy.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

2026-09-30 19:05:07 +02:00

..

from_json.hpp

Re-enable bugprone-use-after-move/hicpp-invalid-access-moved

2026-09-30 19:05:07 +02:00

to_chars.hpp

Route hand-rolled diagnostic pragmas through Hedley (#5485)

2026-09-09 09:48:18 +02:00

to_json.hpp

Test JSON_BRACE_INIT_COPY_SEMANTICS for real, and fix one-element tuples under it (#5544)

2026-09-24 17:05:37 +02:00