C++: Is it safe to cast pointer to int and later back to pointer again?

by

No.

For instance, on x86-64, a pointer is 64-bit long, but int is only 32-bit long. Casting a pointer to int and back again makes the upper 32-bit of the pointer value lost.

You may use the intptr_t type in <cstdint> if you want an integer type which is guaranteed to be as long as the pointer. You could safely reinterpret_cast from a pointer to an intptr_t and back.

More Related Contents:

  1. What is the difference between '.' and '->' when used in array? [closed]
  2. ifstream* Segmentation fault [closed]
  3. A short C++ program about the pointer
  4. C++ Memory Leak Using char *
  5. What are the differences between a pointer variable and a reference variable in C++?
  6. When should static_cast, dynamic_cast, const_cast and reinterpret_cast be used?
  7. How to access a local variable from a different function using pointers?
  8. Why should I use a pointer rather than the object itself?
  9. Typedef function pointer?
  10. Is it safe to delete a NULL pointer?
  11. Why isn’t it legal to convert “pointer to pointer to non-const” to a “pointer to pointer to const”
  12. Correct way of declaring pointer variables in C/C++ [closed]
  13. Reason to Pass a Pointer by Reference in C++?
  14. Uses for multiple levels of pointer dereferences?
  15. Why dereferencing a null pointer is undefined behaviour?
  16. How to use an iterator?
  17. Is the pointer guaranteed to preserve its value after `delete` in C++?
  18. error: invalid initialization of non-const reference of type ‘int&’ from an rvalue of type ‘int’
  19. C++ correct way to return pointer to array from function
  20. Store an int in a char array?
  21. Pointer-to-pointer dynamic two-dimensional array
  22. What does “void *(*)(void *)” mean in C++?
  23. Is pointer comparison undefined or unspecified behavior in C++?
  24. Declaring a pointer to multidimensional array and allocating the array
  25. array decay to pointer and overload resolution
  26. Why am I able to make a function call using an invalid class pointer
  27. Function returning array but main showing garbage [duplicate]
  28. dereferencing a pointer when passing by reference
  29. Why is arr and &arr the same?
  30. Is a Linked-List implementation without using pointers possible or not?

Leave a Comment