const char** parameter warning about char** argument

Question

During compilation of a call to the following function:

char* process_array_of_strings(const char** strings);

GCC complains when a char** is passed as argument:

note: expected ‘const char **’ but argument is of type ‘char **’

While the function does not alter the characters (hence the const) it does duplicate the array of pointers in order to modify the character pointers themselves, so constant pointers are definitely undesirable here.

Compilation succeeds and the program appears to work. So how is the programmer supposed to handle this warning?

Answer 1

Make the conversion explicit with a cast and the compiler will be happy:

process_array_of_strings((const char**) foo);

In these cases you have to explicitly say that you know what you're doing.