1  struct X { int i; int j; };
       2  #define FOO struct X
       3  #define FOO10(x) FOO x ## 0; FOO x ## 1; FOO x ## 2; FOO x ## 3; FOO x ## 4; FOO x ## 5; FOO x ## 6; FOO x ## 7; FOO x ## 8; FOO x ## 9;
       4  #define FOO100(x) FOO10(x ## 0) FOO10(x ## 1) FOO10(x ## 2) FOO10(x ## 3) FOO10(x ## 4) FOO10(x ## 5) FOO10(x ## 6) FOO10(x ## 7) FOO10(x ## 8) FOO10(x ## 9)
       5    FOO100(x0)
       6    FOO100(x1)
       7    FOO100(x2)
       8    FOO100(x3)
       9    FOO100(x4)
      10    FOO100(x5)
      11    FOO100(x6)
      12    FOO100(x7)
      13    FOO100(x8)
      14    FOO100(x9)
      15  
      16  #define COO(n,f) case n: p = &f; break;
      17  #define COO10(n,f) COO(n ## 0, f ## 0) COO(n ## 1, f ## 1) COO(n ## 2, f ## 2) COO(n ## 3, f ## 3) COO(n ## 4, f ## 4) COO(n ## 5, f ## 5) COO(n ## 6, f ## 6) COO(n ## 7, f ## 7) COO(n ## 8, f ## 8) COO(n ## 9, f ## 9)
      18  #define COO100(n,f) COO10(n ## 0, f ## 0) COO10(n ## 1, f ## 1) COO10(n ## 2, f ## 2) COO10(n ## 3, f ## 3) COO10(n ## 4, f ## 4) COO10(n ## 5, f ## 5) COO10(n ## 6, f ## 6) COO10(n ## 7, f ## 7) COO10(n ## 8, f ## 8) COO10(n ## 9, f ## 9)
      19  
      20  int foo(int i)
      21  {
      22    struct X *p = 0;
      23    x000.i = 0;
      24    x599.j = 0;
      25    switch (i)
      26      {
      27    COO100(1, x0)
      28    COO100(2, x1)
      29    COO100(3, x2)
      30    COO100(4, x3)
      31    COO100(5, x4)
      32    COO100(6, x5)
      33    COO100(7, x6)
      34    COO100(8, x7)
      35    COO100(9, x8)
      36    COO100(10, x9)
      37      }
      38    return p->j;
      39  }