})
		}
	}
}

func testBuffer_writeTo(t *testing.T, chunks int, useCopy bool) {
	oldHook := poll.TestHookDidWritev
	defer func() { poll.TestHookDidWritev = oldHook }()
	var writeLog struct {
		sync.Mutex
		log []int
	}
	poll.TestHookDidWritev = func(size int) {
		writeLog.Lock()
		writeLog.log = append(writeLog.log, size)
		writeLog.Unlock()
	}
	var want bytes.Buffer

	for len(*v) > 0 {
		ln0 := int64(len((*v)[0]))
		if ln0 > n {
			(*v)[0] = (*v)[0][n:]
			return
		}
		n -= ln0
		(*v)[0] = nil
		*v = (*v)[1:]
	}
}

// TestHookDidWritev is a hook for testing writev.
var TestHookDidWritev = func(wrote int) {}

// String is an internal string definition for methods/functions
// that is not intended for use outside the standard libraries.
//

			fd.iovecs = new([]syscall.Iovec)
		}
		*fd.iovecs = iovecs // cache

		var wrote uintptr
		wrote, err = writev(fd.Sysfd, iovecs)
		if wrote == ^uintptr(0) {
			wrote = 0
		}
		TestHookDidWritev(int(wrote))
		n += int64(wrote)
		consume(v, int64(wrote))
		clear(iovecs)
		if err != nil {
			if err == syscall.EINTR {
				continue
			}
			if err == syscall.EAGAIN {

	}
	o := &fd.wop
	o.InitBufs(buf)
	n, err := execIO(o, func(o *operation) error {
		return syscall.WSASend(o.fd.Sysfd, &o.bufs[0], uint32(len(o.bufs)), &o.qty, 0, &o.o, nil)
	})
	o.ClearBufs()
	TestHookDidWritev(n)
	consume(buf, int64(n))
	return int64(n), err
}

// WriteTo wraps the sendto network call.
func (fd *FD) WriteTo(buf []byte, sa syscall.Sockaddr) (int, error) {
	if err := fd.writeLock(); err != nil {