Switching on Boolean Conditions and Flags

#ifndef SWITCH_FLAGS_H
#define SWITCH_FLAGS_H

/*
Copyright 2010 Mike Gibson. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the
   distribution.

THIS SOFTWARE IS PROVIDED BY COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.
*/

#define SWITCH_FLAGS_COMBINE(B, V) ((V<<1)|B)

#define SWITCH_FLAGS_MELD(A, B) A: case B

#define SWITCH_FLAGS_A0_F(V) SWITCH_FLAGS_COMBINE(0, V)
#define SWITCH_FLAGS_A0_T(V) SWITCH_FLAGS_COMBINE(1, V)
#define SWITCH_FLAGS_A0_X(V)		  \
	SWITCH_FLAGS_MELD(			  \
		SWITCH_FLAGS_COMBINE(0, V), \
		SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A0(A0) SWITCH_FLAGS_A0_ ## A0(0)

#define SWITCH_FLAGS_A1_F(A0, V) SWITCH_FLAGS_A0_ ## A0(SWITCH_FLAGS_COMBINE(0, V))
#define SWITCH_FLAGS_A1_T(A0, V) SWITCH_FLAGS_A0_ ## A0(SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A1_X(A0, V)					\
	SWITCH_FLAGS_MELD(							\
	    SWITCH_FLAGS_A0_ ## A0(SWITCH_FLAGS_COMBINE(0, V)),	\
		SWITCH_FLAGS_A0_ ## A0(SWITCH_FLAGS_COMBINE(1, V))) 
#define SWITCH_FLAGS_A1(A0, A1) SWITCH_FLAGS_A1_ ## A1(A0, 0)

#define SWITCH_FLAGS_A2_F(A0, A1, V) SWITCH_FLAGS_A1_ ## A1(A0, SWITCH_FLAGS_COMBINE(0, V))
#define SWITCH_FLAGS_A2_T(A0, A1, V) SWITCH_FLAGS_A1_ ## A1(A0, SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A2_X(A0, A1, V)					\
	SWITCH_FLAGS_MELD(								\
	    SWITCH_FLAGS_A1_ ## A1(A0, SWITCH_FLAGS_COMBINE(0, V)),	\
		SWITCH_FLAGS_A1_ ## A1(A0, SWITCH_FLAGS_COMBINE(1, V))) 
#define SWITCH_FLAGS_A2(A0, A1, A2) SWITCH_FLAGS_A2_ ## A2(A0, A1, 0)

#define SWITCH_FLAGS_A3_F(A0, A1, A2, V) SWITCH_FLAGS_A2_ ## A2(A0, A1, SWITCH_FLAGS_COMBINE(0, V))
#define SWITCH_FLAGS_A3_T(A0, A1, A2, V) SWITCH_FLAGS_A2_ ## A2(A0, A1, SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A3_X(A0, A1, A2, V)					\
	SWITCH_FLAGS_MELD(									\
	    SWITCH_FLAGS_A2_ ## A2(A0, A1, SWITCH_FLAGS_COMBINE(0, V)),	\
		SWITCH_FLAGS_A2_ ## A2(A0, A1, SWITCH_FLAGS_COMBINE(1, V))) 
#define SWITCH_FLAGS_A3(A0, A1, A2, A3) SWITCH_FLAGS_A3_ ## A3(A0, A1, A2, 0)

#define SWITCH_FLAGS_A4_F(A0, A1, A2, A3, V) SWITCH_FLAGS_A3_ ## A3(A0, A1, A2, SWITCH_FLAGS_COMBINE(0, V))
#define SWITCH_FLAGS_A4_T(A0, A1, A2, A3, V) SWITCH_FLAGS_A3_ ## A3(A0, A1, A2, SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A4_X(A0, A1, A2, A3, V)					\
	SWITCH_FLAGS_MELD(										\
	    SWITCH_FLAGS_A3_ ## A3(A0, A1, A2, SWITCH_FLAGS_COMBINE(0, V)),	\
		SWITCH_FLAGS_A3_ ## A3(A0, A1, A2, SWITCH_FLAGS_COMBINE(1, V))) 
#define SWITCH_FLAGS_A4(A0, A1, A2, A3, A4) SWITCH_FLAGS_A4_ ## A4(A0, A1, A2, A3, 0)

#define SWITCH_FLAGS_A5_F(A0, A1, A2, A3, A4, V) SWITCH_FLAGS_A4_ ## A4(A0, A1, A2, A3, SWITCH_FLAGS_COMBINE(0, V))
#define SWITCH_FLAGS_A5_T(A0, A1, A2, A3, A4, V) SWITCH_FLAGS_A4_ ## A4(A0, A1, A2, A3, SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A5_X(A0, A1, A2, A3, A4, V)					\
	SWITCH_FLAGS_MELD(											\
	    SWITCH_FLAGS_A4_ ## A4(A0, A1, A2, A3, SWITCH_FLAGS_COMBINE(0, V)),	\
		SWITCH_FLAGS_A4_ ## A4(A0, A1, A2, A3, SWITCH_FLAGS_COMBINE(1, V))) 
#define SWITCH_FLAGS_A5(A0, A1, A2, A3, A4, A5) SWITCH_FLAGS_A5_ ## A5(A0, A1, A2, A3, A4, 0)

#define SWITCH_FLAGS_A6_F(A0, A1, A2, A3, A4, A5, V) SWITCH_FLAGS_A5_ ## A5(A0, A1, A2, A3, A4, SWITCH_FLAGS_COMBINE(0, V))
#define SWITCH_FLAGS_A6_T(A0, A1, A2, A3, A4, A5, V) SWITCH_FLAGS_A5_ ## A5(A0, A1, A2, A3, A4, SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A6_X(A0, A1, A2, A3, A4, A5, V)					\
	SWITCH_FLAGS_MELD(												\
	    SWITCH_FLAGS_A5_ ## A5(A0, A1, A2, A3, A4, SWITCH_FLAGS_COMBINE(0, V)),	\
		SWITCH_FLAGS_A5_ ## A5(A0, A1, A2, A3, A4, SWITCH_FLAGS_COMBINE(1, V))) 
#define SWITCH_FLAGS_A6(A0, A1, A2, A3, A4, A5, A6) SWITCH_FLAGS_A6_ ## A6(A0, A1, A2, A3, A4, A5, 0)

#define SWITCH_FLAGS_A7_F(A0, A1, A2, A3, A4, A5, A6, V) SWITCH_FLAGS_A6_ ## A6(A0, A1, A2, A3, A4, A5, SWITCH_FLAGS_COMBINE(0, V))
#define SWITCH_FLAGS_A7_T(A0, A1, A2, A3, A4, A5, A6, V) SWITCH_FLAGS_A6_ ## A6(A0, A1, A2, A3, A4, A5, SWITCH_FLAGS_COMBINE(1, V))
#define SWITCH_FLAGS_A7_X(A0, A1, A2, A3, A4, A5, A6, V)					\
	SWITCH_FLAGS_MELD(													\
	    SWITCH_FLAGS_A6_ ## A6(A0, A1, A2, A3, A4, A5, SWITCH_FLAGS_COMBINE(0, V)),	\
		SWITCH_FLAGS_A6_ ## A6(A0, A1, A2, A3, A4, A5, SWITCH_FLAGS_COMBINE(1, V))) 
#define SWITCH_FLAGS_A7(A0, A1, A2, A3, A4, A5, A6, A7) SWITCH_FLAGS_A7_ ## A7(A0, A1, A2, A3, A4, A5, A6, 0)

#define SWITCH_FLAGS_S0(A0)                             ((A0) ? 1 : 0)
#define SWITCH_FLAGS_S1(A0, A1)                         (SWITCH_FLAGS_S0(A0) | (SWITCH_FLAGS_S0(A1) << 1))
#define SWITCH_FLAGS_S2(A0, A1, A2)                     (SWITCH_FLAGS_S0(A0) | (SWITCH_FLAGS_S1(A1, A2) << 1))
#define SWITCH_FLAGS_S3(A0, A1, A2, A3)                 (SWITCH_FLAGS_S0(A0) | (SWITCH_FLAGS_S2(A1, A2, A3) << 1))
#define SWITCH_FLAGS_S4(A0, A1, A2, A3, A4)             (SWITCH_FLAGS_S0(A0) | (SWITCH_FLAGS_S3(A1, A2, A3, A4) << 1))
#define SWITCH_FLAGS_S5(A0, A1, A2, A3, A4, A5)         (SWITCH_FLAGS_S0(A0) | (SWITCH_FLAGS_S4(A1, A2, A3, A4, A5) << 1))
#define SWITCH_FLAGS_S6(A0, A1, A2, A3, A4, A5, A6)     (SWITCH_FLAGS_S0(A0) | (SWITCH_FLAGS_S5(A1, A2, A3, A4, A5, A6) << 1))
#define SWITCH_FLAGS_S7(A0, A1, A2, A3, A4, A5, A6, A7) (SWITCH_FLAGS_S0(A0) | (SWITCH_FLAGS_S6(A1, A2, A3, A4, A5, A6, A7) << 1))

#define switch_flags_1(A0)                             switch SWITCH_FLAGS_S0(A0)
#define switch_flags_2(A0, A1)                         switch SWITCH_FLAGS_S1(A0, A1)
#define switch_flags_3(A0, A1, A2)                     switch SWITCH_FLAGS_S2(A0, A1, A2)
#define switch_flags_4(A0, A1, A2, A3)                 switch SWITCH_FLAGS_S3(A0, A1, A2, A3)
#define switch_flags_5(A0, A1, A2, A3, A4)             switch SWITCH_FLAGS_S4(A0, A1, A2, A3, A4)
#define switch_flags_6(A0, A1, A2, A3, A4, A5)         switch SWITCH_FLAGS_S5(A0, A1, A2, A3, A4, A5)
#define switch_flags_7(A0, A1, A2, A3, A4, A5, A6)     switch SWITCH_FLAGS_S6(A0, A1, A2, A3, A4, A5, A6)
#define switch_flags_8(A0, A1, A2, A3, A4, A5, A6, A7) switch SWITCH_FLAGS_S7(A0, A1, A2, A3, A4, A5, A6, A7)

#define flags_1(A0)                         SWITCH_FLAGS_A0(A0)
#define flags_2(A0,A1)                      SWITCH_FLAGS_A1(A0,A1)
#define flags_3(A0,A1,A2)                   SWITCH_FLAGS_A2(A0,A1,A2)
#define flags_4(A0,A1,A2,A3)                SWITCH_FLAGS_A3(A0,A1,A2,A3)
#define flags_5(A0,A1,A2,A3,A4)             SWITCH_FLAGS_A4(A0,A1,A2,A3,A4)
#define flags_6(A0,A1,A2,A3,A4,A5)          SWITCH_FLAGS_A5(A0,A1,A2,A3,A4,A5)
#define flags_7(A0,A1,A2,A3,A4,A5,A6)       SWITCH_FLAGS_A6(A0,A1,A2,A3,A4,A5,A6)
#define flags_8(A0,A1,A2,A3,A4,A5,A6,A7)    SWITCH_FLAGS_A7(A0,A1,A2,A3,A4,A5,A6,A7)

#endif /* SWITCH_FLAGS_H */