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Hi there,

I want to declare an array whose size can be calculated in compile
time. But I as a busy programmer (!) want the compiler to do so. For
example in the following code:

#define N 20 //max number of nodes
#define M 10 //max number of alphabets

int main()
{
const long p2n = pow(2,N)-1;
char f [p2n][p2n][M+1]={0};
}


,how can I say the compiler that p2n is a constant that can be
evaluated in compile time (that's like a simple constant).

Thanks.

ir1979 <ir1...@gmail.com> wrote:
> Hi there,
>
> I want to declare an array whose size can be calculated
> in compile time. But I as a busy programmer (!) want the
> compiler to do so. For example in the following code:
>
> #define N 20 * *//max number of nodes
> #define M 10 * *//max number of alphabets
>
> int main()
> {
> * * const long p2n = pow(2,N)-1;
> * * char f [p2n][p2n][M+1]={0};

Use (1ul << expr).

> }
>
> ,how can I say the compiler that p2n is a constant
> that can be evaluated in compile time (that's like
> a simple constant).

The harder problem is finding an implementation that
supports 10+ terabytes of automatic storage.

--
Peter