IMOH as internals are accessed, that code can only be done by the implementer's of basic_string or at least by the implementers of the standard library providing basic_string. Everything else is a hack.   Thomas (Frederick) stated that the class is not used/called in its unaligned state, so using the 4 bytes of the pointer creatively (either as unaligned byte pointer representation even for char32_t or as I suggested letting it point to the first aligned byte within the SSO buffer) probably has to be done, even if it is violating the class invariant, as long as the class variant is correctly restored, when unpacking to aligned memory.   I understood the example more like a typical user class, which has to cope with unaligned storage.   But perhaps I understood the OP wrongly.   -----Ursprüngliche Nachricht----- Von:Jonathan Wakely <cxx_at_[hidden]> On Thu, 30 Jan 2025 at 10:10, Sebastian Wittmeier via Std-Proposals <std-proposals_at_[hidden] <mailto:std-proposals_at_[hidden]> > wrote: If p is pointing to buf, set it to the first aligned byte of buf in the unaligned memory.  That would break invariants of the libstdc++ basic_string, which uses `p == buf` to detect when the string is no heap allocated. If you point p to the middle of bug then the destructor will do deallocate(p, capacity()+1) which will try to delete non-allocated memory.   The solution is: stop trying to mess with the internals of std::string. Come up with a better motivating example.