[patch] libstdc++/61086 - fix ubsan errors in std::vector

[Paolo Carlini]

On 05/07/2014 02:07 PM, Jonathan Wakely wrote:
> The testcase in the PR calls __position._M_const_cast() to get a
> mutable iterator and that dereferences the pointer as suggested in
> http://gcc.gnu.org/ml/libstdc++/2013-05/msg00031.html
> That's invalid because the pointer is not dereferenceable (in this
> case it's null but is past-the-end at all times).
Uhmm, I see, at the time I scratched my head a bit. Nice that we can 
avoid the whole thing. Are we sure we don't have something similar 
elsewhere?

Paolo.