Say we have this signature:
void frobnicate(const uint8_t* raw_memory, size_t bytes);
Is it possible to write a C++ casting function, that will allow casting an arbitrary type (say, e.g., uint_least8_t or signed char, ...) to an uint8_t* to feed into that function?
All the standard offers is reinterpret_cast and that will of course cast from any pointer type.
By example:
std::vector<int> iv = ...;
std::vector<char> cv = ...;
frobnicate(sized_ptr_cast<const uint8_t*>(iv.data()), iv.size()); // must not compile
frobnicate(sized_ptr_cast<const uint8_t*>(cv.data()), cv.size()); // should compile
Basically a reinterpret_cast with some constraints.
Disclaimers:
f(T*, size_t len) is a good interface and how an iterator based interface would be better off etc.void* please (?) :-)CHAR_BIT == 8Here is an implementation that wrap reinterpret_cast and constrain it with static_assert
template <typename T, typename U>
T sized_ptr_cast(U *p) {
static_assert(std::is_pointer<T>::value, "");
static_assert(sizeof(typename std::remove_pointer<T>::type) == sizeof(U), "size must be same");
return reinterpret_cast<T>(p);
}