void* operator new(size_t s, int hdl) { void* here(mmap(start(), s, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, hdl, 0)); if (MAP_FAILED == here) perror("mmap");  assert(s == size()); assert(here == start()); assert(sysconf(_SC_PAGESIZE) == PageSize);  return here; }
void* operator new(size_t s) { return seed->allocate(s); }
    void* operator new(size_t s, int hdl)        {            void* here(mmap(start(),                            s,                            PROT_READ | PROT_WRITE,                            MAP_SHARED | MAP_FIXED,                            hdl,                            0));            if (MAP_FAILED == here)                perror("mmap");            assert(s == size());            assert(here == start());            assert(sysconf(_SC_PAGESIZE) == PageSize);                return here;        }