> Each of these has an obvious 'output', which is not the case for > something like a comparison operator. This is also an objection > against $(eq) and $(not), which are hidden behind the EXPERIMENTAL > compilation flag.
I think the convection is that an empty string is false while a non-empty string is true. > Otherwise, POSIX prescribes an expr command, so with: > expr = $(shell expr '$1') > you can already do $(call expr,2 * 3 + 5). Ooh I didn't know about that. That seems like a good alternative.
