Fix stack + implement rbt_maze_map()

1 files changed, 3 insertions, 2 deletions

diff --git a/stack.h b/stack.h
index a83a135..68fdb78 100644
--- a/stack.h
+++ b/stack.h
@@ -1,6 +1,7 @@
 #ifndef STACK_H_
 #define STACK_H_
 
+#include <stddef.h>
 #include "structs.h"
 
 /* So, the implementation of the stack is array-based, for hyperspeed.
@@ -15,8 +16,8 @@ struct PositionStack_s {
 typedef struct PositionStack_s PositionStack;
 
 PositionStack ps_new(void); /* Returns an empty position stack */
-int ps_push(PositionStack ps, Position pos); /* Returns -1 if overflow */
-Position ps_pop(PositionStack ps);
+int ps_push(PositionStack *ps, Position pos); /* Returns -1 if overflow */
+Position ps_pop(PositionStack *ps);
 Position ps_peek(PositionStack ps);
 
 #endif /* STACK_H_ */