invalid conversion from ‘const char*’ to ‘char*’ [-fpermissive]

Question

int ::  cadena calculatelenght(const cadena& a, const char* cad)
{
    cadena c;
    int lenght = 0;
    char* punt; punt = cad;
    while(*punt){
        lenght++; punt++;
    }
    return lenght;
}

I have this problem, I want to calculate the length of a C string without using functions like strlen, in other methods of my cadena class I can because is not const char*, but now I don't know what to do.

Answer 1

You can declare punt to be of the correct type:

const char * punt = cad;

Answer 2

You need:

const char* punt; punt = cad;