use void for no-arg functions

Author: Jan Luca van den Busch

include/ballnode.h

@@ -63,6 +63,7 @@ double bnode_dualcount_radius(const BallNode *, const BallNode *, double);
 void bnode_dualcount_range(const BallNode *, const BallNode *, DistHistogram *);
 
 // from ballnode_stats.c
+StatsVector *statvec_new(void);
 StatsVector *statvec_new_reserve(int64_t);
 void statvec_free(StatsVector *);
 int statvec_resize(StatsVector *, int64_t);

src/ballnode.c

@@ -13,7 +13,7 @@ typedef struct {
     double max;
 } Limits;
 
-static Limits limits_new();
+static Limits limits_new(void);
 static void limits_update(Limits *limits, double value);
 static double limits_get_range(Limits *limits);
 
@@ -28,7 +28,7 @@ static Point *ptslc_quickselect(PointSlice *slice, Point *partition, enum Axis a
 static Point *ptslc_partition_maxspread_axis(PointSlice *slice);
 
 
-static Limits limits_new() {
+static Limits limits_new(void) {
     return (Limits){INFINITY, -INFINITY};
 }
 

src/ballnode_stats.c

@@ -4,7 +4,7 @@
 #include "ballnode.h"
 #include "balltree_macros.h"
 
-StatsVector *statvec_new() {
+StatsVector *statvec_new(void) {
     return statvec_new_reserve(32L);
 }