1 files changed, 19 insertions, 0 deletions
diff --git a/prism/util/pm_state_stack.c b/prism/util/pm_state_stack.c
new file mode 100644
index 0000000000..7ff95bd611
--- /dev/null
+++ b/prism/util/pm_state_stack.c
@@ -0,0 +1,19 @@
+#include "yarp/util/yp_state_stack.h"
+
+// Pushes a value onto the stack.
+void
+yp_state_stack_push(yp_state_stack_t *stack, bool value) {
+    *stack = (*stack << 1) | (value & 1);
+}
+
+// Pops a value off the stack.
+void
+yp_state_stack_pop(yp_state_stack_t *stack) {
+    *stack >>= 1;
+}
+
+// Returns the value at the top of the stack.
+bool
+yp_state_stack_p(yp_state_stack_t *stack) {
+    return *stack & 1;
+}