[Bug tree-optimization/121487] False positive -Warray-bounds (triggered via std::ranges::copy and std::string::resize_and_overwrite)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121487

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2025-08-09
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |missed-optimization

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I noticed there is a missing optimization issue:
```
                : n(n_)
        {
                ptr = buffer;
                for (int i = 0; i < 4; ++i) {
                        ptr[i] = static_cast<char>((a & 15) + '0');
                        a >>= 4;
                }
              //  n = n_;
```

The store via ptr is causing issues. If I change it to  be buffer instead of
ptr, the warning is gone. Or if I add a store to n after the loop, the warning
is gone (though not optimized the code is not optimized all the way away).