a=vector3(10,20,30)
a=vector3(10,20)
--a=vector3(10)
--a=vector3()
print(a)

print(a.x,a.y,a.z)
print(a.t,a[1],a[4])

a.x,a.y,a.z=100,200,300
print(a.x,a.y,a.z)