On Thu, 26 Mar 2026 at 21:46, François Dumont <[email protected]> wrote: > > Hi > > Here is the fix to the current COW basic_string issue now that I've > removed the DR438 _GLIBCXX_DEBUG code. > > I've also revisited the location of the debug checks so that for example > on the append_neg.cc test case we have this assertion message with the > cxx11 string: > > In function: > constexpr std::cxx11::basic_string<_CharT, _Traits, _Alloc>& std:: > cxx11::basic_string<_CharT, _Traits, _Alloc>::replace(const_iterator, > const_iterator, _InputIterator, _InputIterator) [with _InputIterator = > > so refering to the replace method. Whereas on the cow string: > > In function: > std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, > _Traits, _Alloc>::append(_InputIterator, _InputIterator) [with > _InputIterator = gnu_debug::_Safe_iterator<gnu_cxx:: > > I plan to do something similar on cxx11 string. Let me know if useless. > > libstdc++: [_GLIBCXX_DEBUG] Fix COW basic_string checks > > In revision 698a6af5dcbae5d935bcda8a461dea8458c658dc the > _GLIBCXX_DEBUG code > for the Library Defect 438 has been removed for C++11 and after. > But the COW > basic_string implementation used when _GLIBCXX_USE_CXX11_ABI=0 was > missing > the _RequireInputIter constraint on a number method resulting in > test failures. > > _RequireInputIter is now added where necessary. And _GLIBCXX_DEBUG > checks have > been added at the right place to benefit from more accurate > assertion messages. > > libstdc++-v3/ChangeLog: > > * include/bits/cow_string.h [__cplusplus >= 201103L] > (basic_string(_InputIte, _InputIte, const _Alloc&)): Add > _RequireInputIter > template parameter. Add > __glibcxx_requires_valid_constructor_range call. > (_M_replace_dispatch(_InputIte, _InputIte): New. > (_M_replace_dispatch(iterator, iterator, _InputIte, > _InputIte): New. > [__cplusplus >= 201103L] > (append(_InputIte, _InputIte)): Add _RequireInputIter > template parameter. > Add __glibcxx_requires_valid_constructor_range call. Use > latter. > (insert(iterator, _InputIte, _InputIte)): Likewise. > (replace(iterator, iterator, _InputIte, _InputIte)): Likewise. > (_S_construct(_InputIte, _InputIte, const _Alloc&)): Add > _RequireInputIter > template parameter. > * include/debug/debug.h > (__glibcxx_requires_valid_construtor_range): New. > * testsuite/21_strings/basic_string/debug/append_neg.cc: > New test case. > * testsuite/21_strings/basic_string/debug/assign_neg.cc: > New test case. > * testsuite/21_strings/basic_string/debug/construct_neg.cc: > New test case. > * testsuite/21_strings/basic_string/debug/insert_neg.cc: > New test case. > * testsuite/21_strings/basic_string/debug/replace_neg.cc: > New test case. > > Tested under Linux x64_86. > > Ok to commit ?
This seems like a large change to stable std::string code, which is inappropriate when we're just a few weeks from releasing GCC 16. I would prefer to just move the assertion macro to _M_replace_dispatch, or only check the assertions for !_Integral, as in the patches I showed. For GCC 17 we can revisit this and apply your fixes.
