[Bug libstdc++/56166] std::string::clear() can throw despite being marked noexcept

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56166

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-01-31
     Ever Confirmed|0                           |1

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-01-31 19:25:27 UTC ---
(In reply to comment #0)
> _M_mutate can allocate memory even when it's being asked to erase the string
> (presumably due to internal reference-counting

If another string shares the same representation then you can't just modify the
representation, you need to create your own clone first, *then* clear it.

For the default configuration we could just point to the shared empty rep, I
wonder why we don't do that.  For the _GLIBCXX_FULLY_DYNAMIC_STRING case we
should probably remove noexcept