Function cap

crawl-ref/source/format.cc:313–321

}

static inline void cap(int &i, int max)
{
    if (i < 0 && -i <= max)
        i += max;
    if (i >= max)
        i = max - 1;
    if (i < 0)
        i = 0;
}

char &formatted_string::operator [] (size_t idx)
{