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Fwd: variadic macro numerber of params
- From: chedi toueiti <chedi dot toueiti at gmail dot com>
- To: gcc-help at gcc dot gnu dot org
- Date: Mon, 26 Apr 2010 15:09:07 +0100
- Subject: Fwd: variadic macro numerber of params
- References: <r2x1c6be81b1004260442o81b717e9g7c0180bfdf649b7a@mail.gmail.com> <u2p1c6be81b1004260704za07c3b1ewcd4c0c339717d9b6@mail.gmail.com>
Hi,
I'm trying to write a macro to process a variable argument list but
need to know exactly the number of argument supplied.
Is there any way to do so with gcc ??
The only solution I found is based on a pseudo fixed limit :
#define PP_NARG(...) PP_NARG_(__VA_ARGS__,PP_RSEQ_N())
#define PP_NARG_(...) PP_ARG_N(__VA_ARGS__)
#define PP_ARG_N( \
_1, _2, _3, _4, _5, _6, _7, _8, _9,_10,
_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28,_29,_30,
_31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \
_41,_42,_43,_44,_45,_46,_47,_48,_49,_50,
_51,_52,_53,_54,_55,_56,_57,_58,_59,_60,_61,_62,_63,N,...) N
#define PP_RSEQ_N() \
63,62,61,60,59,58,57,56,55,54,53,52,51,50,49,48,47,46,45,44,43,42,41,40,39,38,37,36,35,34,33,32,31,30,29,28,27,26,25,24,23,22,21,20,19,18,17,16,
\
15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0
Regards,