Re: Variant

From:

"Bo Persson" <bop@gmb.dk>

Newsgroups:

microsoft.public.vc.language

Date:

Wed, 28 May 2008 20:41:23 +0200

Message-ID:

<6a5na7F302ge1U1@mid.individual.net>

Fil wrote:

Oh, I didn't expect it to work.
I tried the below:

---------------------------------------------------------------------------

#include <iostream>
using namespace std;

int varSize(int variable)
{
int * pointer;
int * oldPointer;
pointer=&variable;
oldPointer=pointer;
pointer++;
return (int)pointer - (int)oldPointer;
}

void main(void)
{
char c;
short s;
int i;
double d;
cout << varSize(c) << endl ;
cout << varSize(s) << endl ;
cout << varSize(i) << endl ;
cout << varSize(d) << endl ;

system("Pause");
}

---------------------------------------------------------------------------

I would have expected compiling errors because I am passing
variables which aren't of the expected type. But it works. Does
that mean that char, short and double types are converted to int
type before entering the function?

Some are "promoted" and others are converted.

What if I initialize my double
to a value that doesn't fit in the int range of values?

Nothing good actually.

I'll try.

What happens if I pull the trigger on this here shotgun?

I would check the manual first! :-)

I think I have to train a little bit before I can possibly
understand the rest of your message.

If you want to write a function that takes variable types of
parameters, you can try

template<typename T>
int varSize(T variable)
{
return sizeof variable;
}

This will create a different fucntion for each parameter type.

Bo Persson