#include <fontconfig/fontconfig.h>
FcBool FcCharSetDelChar(FcCharSet *fcs, FcChar32 ucs4);
FcBool FcCharSetDelChar
FcCharSetDelChar deletes a single Unicode char from the set, returning FcFalse on failure, either as a result of a constant set or from running out of memory.
Fontconfig version 2.11.0