const char * const versus const char *?

Solution 1:

The latter prevents you from modifying the_string inside print_string. It would actually be appropriate here, but perhaps the verbosity put off the developer.

char* the_string : I can change which char the_string points to, and I can modify the char to which it points.

const char* the_string : I can change which char the_string points to, but I cannot modify the char to which it points.

char* const the_string : I cannot change which char the_string points to, but I can modify the char to which it points.

const char* const the_string : I cannot change which char the_string points to, nor can I modify the char to which it points.

Solution 2:

1. Mutable pointer to a mutable character

   char *p;
   

2. Mutable pointer to a constant character

   const char *p;
   

3. Constant pointer to a mutable character

   char * const p; 
   

4. Constant pointer to a constant character

   const char * const p;