template <char I>
struct Int2Type
{
    enum { value = I };
    typedef Int2Type<I> type;
    typedef typename Int2Type<I+1>::type next;
};
int main(void)
{
    Int2Type<5> i;
}
g++ compiler compiles the above program successfully (as it should) but spits out the same warning message 5 times. If you change digit 5 in main to say 7, it spits out 7 identical warnings! Essentially, the warnings are repeated as many number of times as the integer parameter to the Int2Type template. Please try  g++ "source-file" -o "output-file" -Wall 2>&1 | grep warning