id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	revision
612	Windows compile issue due to macros IN and OUT	Peter Kovacs	Alpar Juttner	"Reported by Szabolcs Horvát on the lemon-user mailing list:

> The following problem caused me a lot of frustration, so I thought I'd share the solution with the rest of you.
>
> I had some working LEMON-based code that I wrote on OS X, but then couldn't compile on Windows due to a few mysterious errors that seemed to come from the LEMON headers and not my own code.
>
> The problem turned out to be that I was using LEMON in conjunction with a C library, which in turn includes <windows.h> on Windows (obviously not on OS X), which in turn defines the macros IN and OUT. LEMON uses these same names as template parameters, hence the errors.
>
> A simple
> #undef IN
> #undef OUT
> before including any LEMON headers will fix the problem. Doing this appears to be completely safe (perhaps LEMON could do it by default):
> https://stackoverflow.com/questions/35907493/in-and-out-macros-in-minwindef-h
>
> Szabolcs"	defect	closed	major	LEMON 1.4 release	core	hg main	fixed