Hello,
the current MSVC compiler deems it necessary to issue
    warning C4053: one void operand for '?:'
for a line with CHECK_FOR_INTERRUPTS(). This boils down to this bit of 
miscadmin.h (line 116 in master):
    #define INTERRUPTS_PENDING_CONDITION() \
        (unlikely(UNBLOCKED_SIGNAL_QUEUE()) ?
            pgwin32_dispatch_queued_signals() : 0, \
         unlikely(InterruptPending))
    #endif
The C spec says that of the possible results of the :? operator, either 
none or both can be void, and pgwin32_dispatch_queued_signals() is void
(and has been as far back as I can find it).
Does that matter?
-- 
Christian