Anything can be aliased by char, unsigned char, std::byte (as well as signed char in C), and usually uint8_t == unsigned char, thus by extension any valid void pointer can be cast to u8*.

Thus void*+size is usually the right type if ones only care for the memory representation of an object (cstring functions like memcpy, etc.)

Most likely one would have both overloads:

    void Hexdump(const void *p, size_t size); // (1)
    
    template<typename T>  // (2)
    inline void Hexdump(const T &obj) {
         return Hexdump(&obj, sizeof(T));
    }

With (2) being a wrapper to (1) that compilers will almost always inline, avoiding monomorphization costs (and (2) can also accept rvalues as argument).

(1) could also take std::span<const u8>, but (void*, size) is the more common idiom, more convenient to use and to read , as it is unambiguous which overload it is.