Patch idea from Debian, but modified considerably in implementation:

[sgt/puzzles] / grid.h

diff --git a/grid.h b/grid.h
index 0116074..217f6da 100644 (file)
--- a/grid.h
+++ b/grid.h
@@ -10,9 +10,7 @@
 #define PUZZLES_GRID_H
 
 /* Useful macros */
-#ifndef SQ
-#  define SQ(x) ( (x) * (x) )
-#endif
+#define SQ(x) ( (x) * (x) )
 
 /* ----------------------------------------------------------------------
  * Grid structures: