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Ron Olson · Guest

Hi all-

I have a class Foo that have an overloaded operator int().:

class Foo
{
public:

Foo(int x) : m_Num(x)
{
}

~Foo()
{
}

void PrintNum(void)
{
cout << "I'm object " << m_Num << endl;
}

operator int()
{
return m_Num;
}

private:

int m_Num;
};

and this works when passing to functions like:

Foo myFoo(6);
NoFun(myFoo);

void NoFun(int blah)
{
cout << blah << endl;
}

Now if I have a vector of Foos:

vector
I can still call NoFun() with:

NoFun(MyFoos[0]); // assume we've put a Foo in the vector

Okay, great.

What I'm stumped on is how to pass a vector of Foos to a function that
wants a pointer to a list of ints:

void Fun(int NumInts, int* Ints)
{

}

which I want to call with:

Fun(MyFoos.size(), &MyFoos[0]);

which in turn gives me Error : function call 'Fun2(unsigned long, Foo
*)' does not match
'Fun2(int, const int *)'
HelloWorld.cp line 74 Fun2(Foos2.size(), &Foos2[0]); // no good

from CodeWarrior 8.

What I'm not sure of is why the operator int() doesn't allow the vector
to be passed as an array of ints, instead of Foos. Though we are passing
the vector as an array, why doesn't the compiler see the operator int()
in this situation? I presume it's because we're passing the vector to a
C-style array, where all the ints have to be there as we're no longer
dealing with objects, just an array of ints, and the vector doesn't do
what I presume is memory magic to make it seem more like an array (I
would imagine that an implementation would be to copy the vector to a
new one, calling on the operator int() and then passing the "copy" to
the function.

On the other hand, maybe this is legal and I'm just doing it wrong. Any
suggestions would be appreciated.

Thanks,

Ron

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Frank Birbacher · Guest

Hi!

Ron Olson wrote:

Ivan Vecerina · Guest

"Ron Olson" <olsonr (AT) panix (DOT) com> wrote

Thomas Richter · Guest

Hi,