>On Fri, 9 Jan 2004 11:23:23 +1100, Luke Mewburn writes:
>>what limitations are there on the expression before the ':?'  ?
>>can we do stuff like
>>	${defined(FOO)||${BAR}!=3D"" :?true:false}

Actually you can - sort of.
Problem is you have to prevent ${BAR} being expanded
until it is passed to Cond_EvalExpression().

So the following:

A?=$${USER} == "$B"
B?=x

x:
	@echo "The answer for '$A' is ${$A:?yes:no}"

produces:

$ make -f /homes/sjg/make-tests/ternary x  
The answer for 'sjg == x' is no
$ make -f /homes/sjg/make-tests/ternary x B=sjg
The answer for 'sjg == sjg' is yes
$

But you can't put the expression directly into the ${:?yes:no} bit.
--sjg