[Bug libstdc++/90934] std::vector self-move-insert yields incorrect result

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90934

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This is undefined behaviour.

[res.on.arguments] p1(1.3) says "If a function argument binds to an rvalue
reference parameter, the implementation may assume that this parameter is a
unique reference to this argument."

You have created an rvalue reference to an object which is already referenced
by the vector itself, so the rvalue reference is not a unique reference.