C ++程序中的指针大小

Question

我知道指针大小取决于系统的体系结构，但是当考虑虚拟内存并且说它大于物理内存时，那么变量指针大小如何受到体系结构的限制？

Answer 1

A pointer must be able to hold the address of any location in memory. As a result, a 32 bit system (usually) needs a 32 bit pointer!

Note the "usually" here, as member function pointers can be completely different in size and there are many other exceptions to this rule of thumb. If in doubt, or it matters a lot, write a quick program to check on the architecture you're targeting.