DWORD size_high;
DWORD size_low = GetFileSize(fd, &size_high);
HANDLE mmap = CreateFileMapping(fd, nullptr, PAGE_READONLY, size_high, size_low, nullptr);
DWORD size_high;
DWORD size_low = GetFileSize(fd, &size_high);
HANDLE mmap = CreateFileMapping(fd, nullptr, PAGE_READONLY, size_high, size_low, nullptr);