[PATCH][_GLIBCXX_DEBUG] Remove useless checks

[François Dumont]

On 23/01/23 10:22, Jonathan Wakely wrote:
> On Mon, 23 Jan 2023 at 06:02, François Dumont via Libstdc++
> <libstdc++@gcc.gnu.org> wrote:
>>       libstdc++: [_GLIBCXX_DEBUG] Remove useless constructor checks
>>
>>       Creating a safe iterator from a normal iterator is done within the
>> library where we
>>       already know that it is done correctly. The rare situation where a
>> user would use safe
>>       iterators for his own purpose is non-Standard code so outside
>> _GLIBCXX_DEBUG scope. For
>>       those reasons the __msg_init_singular is useless and can be removed.
>>
>>       Additionally in the copy constructor used for post-increment and
>> post-decrement operators
>>       the __msg_init_copy_singular check can also be ommitted because of
>> the preliminary
>>       __msg_bad_inc and __msg_bad_dec checks.
>>
>>       libstdc++-v3/ChangeLog:
>>
>>               * include/debug/safe_iterator.h
>> (_Safe_iterator<>::_Unsafe_call): New.
> I don't like the name "unsafe call". Why is it unsafe? As you say
> above, we don't need to check because we know that it's only called in
> a context where it's safe. Can we call it _Unchecked instead of
> _Unsafe_call? That seems like a more accurate description of the
> behaviour.
>
>
>>               (_Safe_iterator(const _Safe_iterator&, _Unsafe_call): New.
>>               (_Safe_iterator::operator++(int)): Use latter.
>>               (_Safe_iterator::operator--(int)): Likewise.
>>               (_Safe_iterator(_Iterator, const _Safe_sequence_base*)):
>> Remove !_M_insular()
>>               check.
>>               * include/debug/safe_local_iterator.h
>> (_Safe_local_iterator<>::_Unsafe_call):
>>               New.
>>               (_Safe_local_iterator(const _Safe_local_iterator&,
>> _Unsafe_call): New.
>>               (_Safe_local_iterator::operator++(int)): Use latter.
>>               * src/c++11/debug.cc (_S_debug_messages): Add as comment
>> the _Debug_msg_id
>>               entry associated to the array entry.
> These comments are a great idea, thanks.
>
> If you agree with the _Unchecked name, OK to commit with that change.
>
It's unsafe because it's unchecked so _Unchecked is fine for me too :-)

Committed with the requested change.

Thanks