FcUcs4ToUtf8 − convert UCS4 to UTF-8
#include <fontconfig/fontconfig.h>
int FcUcs4ToUtf8 (FcChar32 src, FcChar8 dst[FC_UTF8_MAX_LEN]);
Converts the Unicode char from src into dst and returns the number of bytes needed to encode the char.
Fontconfig version 2.10.95