将指针地址转换为 int

Question

Beginner question: How can I take the adress of a pointer and save it as an int? Example:

int *ptr = xyz;
int i = static_cast<int>(ptr);

So if ptr points to the memory adress 123, i should be 123. My compiler says it's an error: invalid static_cast from type 'int*' to type 'int' .

Guess I am missing something but I don't know what.

Answer 1

You can use reinterpret_cast . An int is not guaranteed to be able to losslessly store a pointer though, so you should use the std::intptr_t type instead.

Answer 2

You can also use C-style casting:

int *ptr = xyz;
int i = (int) ptr;

Here's a nice discussion comparing C-style casting to reinterpret_cast .

Answer 3

you can use the following function to get any pointer as unsigned long. int is not guaranteed to fulfill the task.

template <typename T>
static constexpr inline auto ptrToAddr(T *pointer) noexcept
{
  return reinterpret_cast<std::uintptr_t>(pointer);
}