#ifndef main

[address@hidden]

I have two files and the contents are as follows :

file :: main.h
-------------------------------------
#ifndef main
#define main

#endif
--------------------------------------
file :: main.cpp
-------------------------------------
#include "main.h"

int main(void)
{
return 0 ;
}
------------------------------------

This program does not compile and the error message that I get is ::
expected unqualified-id before ‘void’
expected `)' before ‘void’

After some digging I have established that the problem lies in the
line
#ifndef main
If I change it to
#ifndef Main or #ifndef MAIN etc it works

May somebody please shed some light on this ?

Thanks