Function Pointer

[santosh]

class MyClass
{
private:
static int a;
float b;
char c;

public:
MyClass():b(0),c('\0'){};
static int DoMore(int p_a)
{
a=a+p_a;
cout<<"a="<<a<<endl;
return a;
}
float Increment(float p_f)
{
b+=p_f;
cout<<"b="<<b<<endl;
return b;
}
};
int main(void)
{
int (MyClass::*fn_ptr1)(int);
fn_ptr1=&MyClass:oMore;
fn_ptr1(5);
return 0;
}

Here I am getting Compilation error.
If I write like this bellow, It is OK(working)

int main(void)
{
int (*fn_ptr1)(int);
fn_ptr1=&MyClass:oMore;
fn_ptr1(5);
return 0;
}

Why it is so?

 

[Jonathan Bartlett]

Here I am getting Compilation error.

If I write like this bellow, It is OK(working)

Static methods are basically just normal functions with a different
scope. They are NOT real methods of an object, and therefore, the
method syntax doesn't work.

Jon

 

[Mike Wahler]

class MyClass
{
private:
static int a;
float b;
char c;

public:
MyClass():b(0),c('\0'){};
static int DoMore(int p_a)
{
a=a+p_a;
cout<<"a="<<a<<endl;
return a;
}
float Increment(float p_f)
{
b+=p_f;
cout<<"b="<<b<<endl;
return b;
}
};
int main(void)
{
int (MyClass::*fn_ptr1)(int);
fn_ptr1=&MyClass:oMore;
fn_ptr1(5);
return 0;
}

Here I am getting Compilation error.
If I write like this bellow, It is OK(working)

int main(void)
{
int (*fn_ptr1)(int);
fn_ptr1=&MyClass:oMore;
fn_ptr1(5);
return 0;
}

Why it is so?

Because 'MyClass:oMore()' is declared 'static'.

For more information, see this section of the
C++ FAQ:
http://www.parashift.com/c++-faq-lite/pointers-to-members.html

-Mike