diff --git a/treeset/Makefile b/treeset/Makefile
new file mode 100644
index 0000000..6dae1fd
--- /dev/null
+++ b/treeset/Makefile
@@ -0,0 +1,14 @@
+CC = gcc
+CFLAGS = -Wall -O2
+
+TARGET = main.elf
+SRC = main.c treeset.c
+
+#LDFLAGS =
+
+$(TARGET): $(SRC)
+	@echo CC $@
+	@$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+
+clean:
+	rm -f $(TARGET)
diff --git a/treeset/main.c b/treeset/main.c
new file mode 100644
index 0000000..34517c4
--- /dev/null
+++ b/treeset/main.c
@@ -0,0 +1,7 @@
+#include "treeset.h"
+#include <stdio.h>
+
+int main() {
+    treeset_t tree = {};
+    return 0;
+}
diff --git a/treeset/treeset.c b/treeset/treeset.c
new file mode 100644
index 0000000..7f0aba6
--- /dev/null
+++ b/treeset/treeset.c
@@ -0,0 +1,25 @@
+#include "treeset.h"
+#include <stdlib.h>
+#include <string.h>
+
+struct treeset_node {
+    void *data;
+    struct treeset_node *left;
+    struct treeset_node *right;
+};
+
+struct treeset {
+    treeset_node_t *root;
+    size_t node_count;
+};
+
+void ts_node_destroy(treeset_node_t *n) {
+    if (n->left != NULL)
+        ts_node_destroy((treeset_node_t *)n->left);
+    if (n->right != NULL)
+        ts_node_destroy((treeset_node_t *)n->left);
+
+    free(n);
+}
+
+void treeset_destroy(treeset_t *set) { ts_node_destroy(set->root); }
diff --git a/treeset/treeset.h b/treeset/treeset.h
new file mode 100644
index 0000000..59ef483
--- /dev/null
+++ b/treeset/treeset.h
@@ -0,0 +1,26 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef struct treeset treeset_t;
+typedef struct treeset_node treeset_node_t;
+
+/*
+ * Cast a and b to your custom struct and return:
+ * 1 for greater than
+ * -1 for less than
+ *  0 for equal
+ */
+int treeset_demo_cmp(void *a, void *b) {
+    if (*((int *)a) > *((int *)a))
+        return -1;
+    if (*((int *)a) < *((int *)a))
+        return 1;
+
+    return 0;
+}
+
+void treeset_destroy(treeset_t *set);
+void put(treeset_t *set, void *data, int (*cmp)(void *, void *));
+// contains
+// remove