Add UP_CAST macro, for safer casting from contained data to its container.

[pspp-builds.git] / src / math / tukey-hinges.c

diff --git a/src/math/tukey-hinges.c b/src/math/tukey-hinges.c
index ded7a9c6fe4233baa3172899c467e38770023b07..22ab45210c38c98066eb4bb654663114cb496ddd 100644 (file)
--- a/src/math/tukey-hinges.c
+++ b/src/math/tukey-hinges.c
@@ -20,6 +20,7 @@
 
 #include <gl/xalloc.h>
 #include <libpspp/assertion.h>
+#include <libpspp/cast.h>
 #include <math.h>
 
 void
@@ -59,7 +60,8 @@ tukey_hinges_calculate (const struct tukey_hinges *th, double hinge[3])
 static void
 destroy (struct statistic *s)
 {
-  struct order_stats *os = (struct order_stats *) s;
+  struct tukey_hinges *th = UP_CAST (s, struct tukey_hinges, parent.parent);
+  struct order_stats *os = &th->parent;
 
   free (os->k);
   free (s);