http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51609
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-12-19 02:24:24 UTC --- While I agree the code is reasonable, I think an LWG issue is needed, because I don't think GCC's behaviour is in conflict with the standard. I don't read [unique.ptr.runtime] p1 b2 as requiring that cv-qualified types must be accepted. It only says types derived from T are rejected, which GCC does. The standard defines exactly these overloads: void reset(pointer p = pointer()) noexcept; void reset(nullptr_t) noexcept; template <class U> void reset(U) = delete; and there is nothing in [unique.ptr.runtime.modiļ¬ers] to constrain the template.