[C++应用程序性能优化]单继承

class simpleClass
{
public:
static int n_count;
int n_value;
char c;
simpleClass() { printf("Create base class.\n"); }
virtual ~simpleClass() { printf("Destroy base class.\n"); }
int get_value(void);
virtual void foo(void) { printf("foo in base class.\n"); }
static void add_count();
};

class dsimpleClass : public simpleClass
{
public:
int n_sub_value;
dsimpleClass() { printf("create derived class.\n\n"); }
~dsimpleClass() { printf("destroy derived class.\n"); }
virtual void foo() { printf("foo in derived class.\n"); }
};

#include <stdlib.h>
#include <stdio.h>
#include "gtest.h"

int simpleClass::n_count = 0;
int main()
{
dsimpleClass asimple;
printf("Object start address: %x\n", &asimple);
printf("n_value address: %x\n", &asimple.n_value);
printf("c address: %x\n", &asimple.c);
printf("n_subvalue address: %x\n", &asimple.n_sub_value);
printf("base class size: %d ; derived class size: %d\n\n", sizeof(simpleClass), sizeof(dsimpleClass));
system("pause");
return 0;
}