The resulting pointer is unspecified: means dereferencing it is UB.Because the compiler is not allowed to alter the bits of A. It will keep it as given.I can do the following.double* ptr = reinterpret_cast<double*>(0x7fff934a9d83); // misaligned for doubleptr value will stay 0x7fff934a9d83, but it is unusable otherwise:*ptr is UB++ptr is UB--ptr is UBptr+int the result is UB....etcSent from my Galaxy
-------- Original message --------From: Sebastian Wittmeier via Std-Proposals <std-proposals_at_[hidden]> Date: 1/28/25 3:40 PM (GMT+01:00) To: std-proposals_at_[hidden] Cc: Sebastian Wittmeier <wittmeier_at_[hidden]> Subject: Re: [std-proposals] Make all data pointers intercompatible
According to CPP Reference this is currently not okay:"If expression represents the address A of a byte in memory but A does not satisfy the alignment requirement of T, then the resulting pointer value is unspecified."https://en.cppreference.com/w/cpp/language/static_cast -----Ursprüngliche Nachricht-----Von: organicoman via Std-Proposals <std-proposals_at_[hidden]>No it could not, and it is not allowed. The only thing you will MAYBE get is a misaligned pointer to a double memory location, and you should not dereference that pointer, because of aliasing incompatibility otherwise UB. Try the following code:#include <stdio.h>int main(){ char arr[8]; double* ptr = static_cast<double*>(static_cast<void*>(arr+3));