I ran across something curious in C++. I have always associated the using directive with namespaces, but this one I have not encountered until now.
I saw something like the following code in my work and have not found an explanation of why the code works as it does.
test.cpp:
Code:
#include <stdio.h>
class test1
{
protected:
virtual void afunct() =0;
};
class test2 : public test1
{
public:
void afunct(void);
};
class test3 : protected test2
{
public:
void bfunct(void);
using test2::afunct;
};
void test2::afunct(void)
{
printf("afunct()\n");
}
void test3::bfunct(void)
{
printf("bfunct()\n");
}
void main()
{
test2 v1;
test3 v2;
v1.afunct();
v2.bfunct();
v2.afunct();
}
I compile and run it and it works. Comment out the using directive and afunct() is not accessible through class test3. Part of my confusion may be due to the fact that I never really got the hang of protected.
I am just curious as to how/why it works the way it does.