unnamed type definition in parentheses

[legendsoft]

when I use vc6 to compile a driver.

I get the error:
error C4116: unnamed type definition in parentheses

this is the code that the error point to:
ProbeForRead(Irp->UserBuffer, pIoStackIrp->Parameters.Write.Length, TYPE_ALIGNMENT(char));

what does TYPE_ALIGNMENT(char)) mean, and why it case the error?