diff --git a/c/swap.h b/c/swap.h
new file mode 100644
index 0000000..f24d2fe
--- /dev/null
+++ b/c/swap.h
@@ -0,0 +1,5 @@
+#include <stddef.h>
+
+void swap_loop(char* restrict a, char* restrict b, size_t len);
+void swap_malloc(char* restrict a, char* restrict b, size_t len);
+void swap_alloca(char* restrict a, char* restrict b, size_t len);