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December 2008
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2008.12.18 16:16 "Re: tiffvers.h - TIFFLIB_RELEASE macro addition", by Bob Friesenhahn
On Thu, 18 Dec 2008, Frank Warmerdam wrote: >> >> The available values are CURRENT, REVISION, and AGE in order of decreasing >> significance. For example, CURRENT might be 4. > > But this is not normally conveniently available to applications building > against libtiff, right? It requires some sort of configure magic to > extract the libtool versioning and represent it as macros passed into > the application. It wouldn't do anything for someone on windows for > instance. Right. That is where the substitution magic which builds tiffvers.h comes in. Then the versioning info is available to all. It is not difficult for configure/make to maintain a continually up to date tiffvers.h. >> The approach you describe still only works if the major release update >> always offers additional features over the previous major release. > > I do not understand this comment. What I mean is your use of arbitrary libtiff version numbers to determine if a feature is available. Features can be backported and it is even possible that a lesser numbered library supports a feature which is not available in a higher numbered library. Bob ====================================== Bob Friesenhahn bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/