_CP_sum is equivalent to the result = sum(string) BASIC statement.
int _CP_sum(CPSTR** result, CPSTR* string)
This function returns -1 if an error occurs. The error code is contained in _CP_errno.
/* Prints "3". */ CPSTR * s = _CP_mkstr("1\3762"); _CP_sum(&s,s); _CP_print(s);