C++ :: String Reverse Function - Array Declaration

Here's my program: - Program which inputs a string from user, reverses it and displays it.

#include <iostream>
using namespace std;
void string_reverse (char [], const int);
int main() {
const int arraysize = 10;
char string[arraysize];

[Code] ....

In the string_reverse function, I have declared temp character type array but on line 38, the

compiler is throwing 3 errors: -

error C2057: expected constant expression
error C2466: cannot allocate an array of constant size 0
error C2133: 'temp' : unknown size

I have declared a constant integer arraysize in line 35. Now I have no clue why is this happening because I think as I have declared it as a constant integer variable, this should not happen.