c++ - Is the sizeof(some pointer) always equal to four?

For example:
sizeof(char*) returns 4. As does int*, long long*, everything that I've tried. Are there any exceptions to this?

Answer

The guarantee you get is that sizeof(char) == 1. There are no other guarantees, including no guarantee that sizeof(int *) == sizeof(double *).

In practice, pointers will be size 2 on a 16-bit system (if you can find one), 4 on a 32-bit system, and 8 on a 64-bit system, but there's nothing to be gained in relying on a given size.