// The const keyword has a number of interactions with
// pointer and reference declarations, depending on the placement
//  of the const.  In fact, more than one const can appear in such
//  a declaration!


#include <stream.h>
main()
{
// Case 0:  no const
// Our old friend the pointer to a character
    char * p0 = "A simple string";

// Case 1: pointer to a const char
// We can change the pointer, but not what it points to
    const char * p1 = "A pointer to const char";

// This is legal
    p1++;

// This is not
    p1[2] = 'x';

// But we can't change the pointer itself
    char * const p2 ="This is a constant pointer";

// We  can modify what p2 points to
// This is legal
    p2[2] = 'u';  // Changes the 'i' to a 'u'.

// Case 2:  A constant pointer to a char 
// This is not legal
    p2++;


// Case 3: A constant pointer to a constant char 
//  We can't change either q or *q
    const char * const p3 = "A constant pointer to a constant";

// Neither of these is legal
    p3[2] = 'u';
    p3++;
}