+@RET@ FcBool
+@FUNC@ FcCharSetMerge
+@TYPE1@ FcCharSet * @ARG1@ a
+@TYPE2@ const FcCharSet * @ARG2@ b
+@TYPE3@ FcBool * @ARG3@ changed
+@PURPOSE@ Merge charsets
+@DESC@
+Adds all chars in <parameter>b</parameter> to <parameter>a</parameter>.
+In other words, this is an in-place version of FcCharSetUnion.
+If <parameter>changed</parameter> is not NULL, then it returns whether any new
+chars from <parameter>b</parameter> were added to <parameter>a</parameter>.
+Returns FcFalse on failure, either when <parameter>a</parameter> is a constant
+set or from running out of memory.
+@@
+