#define ARRAY_LEN(array) (sizeof(array) / sizeof(array[0]))
#define swap(a, b) ({ typeof(a) __a = (a); typeof(b) __b = (b); \
#define ARRAY_LEN(array) (sizeof(array) / sizeof(array[0]))
#define swap(a, b) ({ typeof(a) __a = (a); typeof(b) __b = (b); \