-# b4_define_flag_if(FLAG)
-# -----------------------
-# Define "b4_FLAG_if(IF-TRUE, IF-FALSE)" that depends on the
-# value of the Boolean FLAG.
-m4_define([b4_define_flag_if],
-[_b4_define_flag_if($[1], $[2], [$1])])
-
-# _b4_define_flag_if($1, $2, FLAG)
-# --------------------------------
-# This macro works around the impossibility to define macros
-# inside macros, because issuing `[$1]' is not possible in M4 :(.
-# This sucks hard, GNU M4 should really provide M5 like $$1.
-m4_define([_b4_define_flag_if],
-[m4_if([$1$2], $[1]$[2], [],
- [m4_fatal([$0: Invalid arguments: $@])])dnl
-m4_define([b4_$3_if],
- [b4_flag_if([$3], [$1], [$2])])])