Function std::html_unescape

void html_unescape(&String out, const &char s)

The reverse: appends 's' to 'out' with character references decoded — numeric (''', '—', as UTF-8) and the common named ones (amp lt gt quot apos nbsp, plus copy reg trade hellip mdash ndash lsquo rsquo ldquo rdquo laquo raquo middot bull times divide deg larr rarr uarr darr harr ne le ge); anything else is copied as-is.