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

[pspp-builds.git] / src / output / charts / piechart.c

diff --git a/src/output/charts/piechart.c b/src/output/charts/piechart.c
index c6e6b24f653f04df87090619d2d21a4956853155..935c6eb0fed9784024c54e571e53936e07c09c7b 100644 (file)
--- a/src/output/charts/piechart.c
+++ b/src/output/charts/piechart.c
@@ -26,6 +26,7 @@
 #include <stdio.h>
 
 #include <data/value-labels.h>
+#include <libpspp/cast.h>
 #include <libpspp/str.h>
 #include <output/charts/plot-chart.h>
 #include <output/chart-provider.h>
@@ -80,7 +81,7 @@ static void
 piechart_draw (const struct chart *chart, cairo_t *cr,
                struct chart_geometry *geom)
 {
-  struct piechart *pie = (struct piechart *) chart;
+  const struct piechart *pie = UP_CAST (chart, struct piechart, chart);
   double total_magnitude;
   double left_label, right_label;
   double centre_x, centre_y;
@@ -176,7 +177,7 @@ draw_segment(cairo_t *cr,
 static void
 piechart_destroy (struct chart *chart)
 {
-  struct piechart *pie = (struct piechart *) chart;
+  struct piechart *pie = UP_CAST (chart, struct piechart, chart);
   int i;
 
   free (pie->title);