Documentation: update tutorial's discussion of origin

diff --git a/interpolate.h b/interpolate.h
index a55fb8e0714487a2107e7cfb0e451d2b5e022b01..190a180b587aa565ae2ae71f9eb068ad75db168f 100644 (file)
--- a/interpolate.h
+++ b/interpolate.h
@@ -16,7 +16,7 @@ struct interp {
        char *value;
 };
 
-extern void interp_set_entry(struct interp *table, int slot, char *value);
+extern void interp_set_entry(struct interp *table, int slot, const char *value);
 extern void interp_clear_table(struct interp *table, int ninterps);
 
 extern int interpolate(char *result, int reslen,