Apply Rule of Zero across remaining utility/ empty destructors#694
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lyskov-ai wants to merge 1 commit into
Open
Apply Rule of Zero across remaining utility/ empty destructors#694lyskov-ai wants to merge 1 commit into
lyskov-ai wants to merge 1 commit into
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Remove user-declared destructors and out-of-line `= default` definitions
where the implicit (or `= default`) destructor is correct, and clarify a
non-trivial destructor by deleting copy/move on its owner.
* Remove empty `~Foo() {}` / `~Foo() override {}` where the implicit
destructor is already correct (and virtual via base when needed):
- utility/Bound.hh, utility/excn/Exceptions.hh,
utility/io/ocstream.hh, utility/keys/AutoKey.hh,
utility/keys/UserKey.hh.
* Convert `~Foo() {}` to `~Foo() = default;` for polymorphic root
classes whose implicit destructor would otherwise be non-virtual:
- utility/Show.hh, utility/factory/WidgetFactory.hh,
utility/io/irstream.hh, utility/io/orstream.hh,
utility/keys/Key.hh, utility/options/Option.hh.
* Drop `= default` destructor pairs (.hh declaration + .cc definition)
for classes inheriting from utility::VirtualBase, which already
supplies a virtual destructor:
- utility/heap, utility/integer_mapping (subset_mapping),
utility/recent_history_queue, utility/io/GeneralFileManager
(GeneralFileContents{,Vector}), utility/tag/Tag.
* utility/io/mpistream.hh: explicitly `= delete` the copy ctor and
copy assignment of `basic_mpi_streambuf` because its destructor
calls `flush_final()` (closes the MPI channel); replace the empty
`~basic_mpi_ostream() override {}` with `= default`.
lyskov
approved these changes
May 12, 2026
roccomoretti
approved these changes
May 18, 2026
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Summary
Bundle of small Rule-of-Zero / clarity fixes across
utility/for classesnot covered by any other open PR. All changes are observably no-ops at
runtime (each destructor body either was empty or
= default); the goalis to remove redundant declarations and document a deliberate non-trivial
case.
~Foo() {}where the implicit destructor is alreadycorrect (virtual is preserved via the base class when relevant):
Bound,Exception,ocstream,AutoKey,UserKey.~Foo() {}to~Foo() = default;for polymorphic rootclasses (no virtual base destructor to inherit), so the destructor
stays virtual:
Show,WidgetFactory,irstream,orstream,Key,Option.= defaultdestructor pairs (.hh decl + .cc def) forclasses that inherit from
utility::VirtualBase, which alreadysupplies a
virtual ~VirtualBase() = default;:heap,subset_mapping,recent_history_queue,GeneralFileContents,GeneralFileContentsVector,Tag.utility/io/mpistream.hh: the destructor ofbasic_mpi_streambufis not trivial — it calls
flush_final(), which sends the closemessage on the MPI channel. Add explicit
= deletefor its copyconstructor and copy-assignment so an accidental copy can't trigger
the side effect twice. Also replace the empty
~basic_mpi_ostream() override {}with= default.The diff is intentionally smaller than the usual 128-line bundle target:
most other empty-destructor candidates in
utility/are already coveredby my open sibling PRs (#690 BitSet/BitVector, #691 keys containers, #692
utility/ helpers, #693 utility/options empty dtors). This PR sweeps the
classes those don't touch.
Verified by a clean
mode=debugbuild (python3 ./scons.py -j16 mode=debug,zero errors, no new warnings).