#include <unistd.h>

void swab(const void* restrict _src, void* restrict _dest, ssize_t n) {
  const char* src = _src;
  char* dest = _dest;
  for (; n > 1; n -= 2) {
    dest[0] = src[1];
    dest[1] = src[0];
    dest += 2;
    src += 2;
  }
}