// filename:c2011-5-2-1-1-ex.c
// original examples and/or notes:
// 		(c) ISO/IEC JTC1 SC22 WG14 N1570, April 12, 2011
// http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf
// 			C2011 5.2.1.1 Trigraph sequences
// compile and output mechanism:
// 		(c) Ogawa Kiyoshi, kaizen@gifu-u.ac.jp, December.xx, 2013
// compile errors and/or wornings:
// 1	(c) Apple LLVM version 4.2 (clang-425.0.27) (based on LLVM 3.2svn)
// 			Target: x86_64-apple-darwin11.4.2 //Thread model: posix
// 		(c) LLVM 2003-2009 University of Illinois at Urbana-Champaign.
// 2    gcc-4.9 (GCC) 4.9.0 20131229 (experimental)
//      Copyright (C) 2013 Free Software Foundation, Inc.
//EXAMPLE 1
// ??=define arraycheck(a, b) a??(b??) ??!??! b??(a??)
// becomes
// #define arraycheck(a, b) a[b] || b[a]
//EXAMPLE 2 The following source line
// printf("Eh???/n");
// becomes (after replacement of the trigraph sequence ??/)
// printf("Eh?\n");
// add initialization of b because of GCC4.9 cause "Segmentation fault: 11"
??=define arraycheck(a, b) a??(b??) ??!??! b??(a??)
#include <stdio.h>
int main(void){
int a[1],b=0;
return printf("%d Eh???/n",arraycheck(a,b));
}
//  warning: trigraph ignored [-Wtrigraphs]
// cc -trigraphs c2011-5-2-1-1-ex.c or gcc -trigraphs c2011-5-2-1-1-ex.c
// 1 Eh?