[boost] String Algorithms Library: Case insensitive compare UTF-8

Anyone who knows how this could be made possible? I suppose I need a locale facet like the std::ctype, but which works for UTF-8, and not just for ASCII a-z,A-Z. I guess the information in a table like this (http://www.unicode.org/Public/UNIDATA/CaseFolding.txt) could be used. If it's better/easier just to convert the string to UTF-32 before doing case insensitive compares, replaces I could live with that. -Regards Martin Lütken