[Bug tree-optimization/114758] The layout of a std::vector reports a warning

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114758

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2025-03-28
           Assignee|unassigned at gcc dot gnu.org      |redi at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Which gave me an idea how to change the library code to avoid the problem:

--- a/libstdc++-v3/include/bits/vector.tcc
+++ b/libstdc++-v3/include/bits/vector.tcc
@@ -1134,11 +1134,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
        {
          const size_type __len = 
            _M_check_len(__n, "vector<bool>::_M_fill_insert");
+         iterator __begin = begin(), __end = end();
          _Bit_pointer __q = this->_M_allocate(__len);
          iterator __start(std::__addressof(*__q), 0);
-         iterator __i = _M_copy_aligned(begin(), __position, __start);
+         iterator __i = _M_copy_aligned(__begin, __position, __start);
          std::fill(__i, __i + difference_type(__n), __x);
-         iterator __finish = std::copy(__position, end(),
+         iterator __finish = std::copy(__position, __end,
                                        __i + difference_type(__n));
          this->_M_deallocate();
          this->_M_impl._M_end_of_storage = __q + _S_nword(__len);