virtual function and virtual table size in C + +

Experiment with the following function:

#include <vector>#include<iostream>using namespacestd;classA { Public:    Virtual intA () {}Virtual intB () {}Virtual intC () {}Virtual intd () {}Virtual inte () {}Virtual intf () {}Virtual intg () {}intt;};intMain () {a A; cout<<sizeof(a) <<Endl; return 0;}

Output:

16

Why is it 16? Because I'm using a 64-bit machine.

the pointer size of a 64-bit machine is 8.

And then because of the alignment, so the entire length is 16.

Note : Inside the 64-bit machine, the size of int is still 4.

The contents of the virtual table of virtual functions are written in the March 2 article.

virtual function and virtual table size in C + +