Function NextString

src/test/util/str.h:17–25

 */
template <typename CharType, size_t StringLength>
bool NextString(CharType (&string)[StringLength], CharType min_char, CharType max_char)
{
    for (CharType& elem : string) {
        bool has_next = elem != max_char;
        elem = elem < min_char || elem >= max_char ? min_char : CharType(elem + 1);
        if (has_next) return true;
    }
    return false;
}

/**
 * Iterate over string values and call function for each string without