#include <fontconfig/fontconfig.h>
FcLangResult FcLangSetHasLang (const FcLangSet *ls, const FcChar8 *lang);
FcLangSetHasLang checks whether ls supports lang. If ls has a matching language and territory pair, this function returns FcLangEqual. If ls has a matching language but differs in which territory that language is for, this function returns FcLangDifferentTerritory. If ls has no matching language, this function returns FcLangDifferentLang.