But, assuming header is a standard layout type, the following: header h; read((char*)&h, sizeof(h)); get_destination(h).write((const char*)&h, sizeof(h))

But, assuming header is a standard layout type, the following: header h; read((char*)&h, sizeof(h)); get_destination(h).write((const char*)&h, sizeof(h)); Is well defined even under strict aliasing. (agree about the two views being live at the same time and memcpy being suboptimal here).