On 06/26/14 06:15, Shuai Meng wrote: > I think over these codes again, ~VT_TYPEMASK is equal to 0, V_VT(arg) & > ~VT_TYPEMASK will always be equal to 0, and then the codes belong to > this if branch will never be executed, so why we write them? ~VT_TYPEMAST is not equal to 0.