Hartmut Kaiser wrote:
Stefan,
I'm not sure where the -lpthread needs to be added (I added it manually to the link command and it succeeded), or in fact, why wave links to boost_thread at all. It doesn't use threads underneath, or does it ? It turns out the dependency on boost_thread is dragged in by boost.spirit. (I modified the subject line to reflect this.)
I'm not sure in what way boost_thread is used there, but I would hope that the decision to use threads (and boost_thread) could be left to the library's user. Only pay for what you really use, or so the saying goes...
Is it possible to modify the config logic to have some users only use the subset of boost.spirit that doesn't require boost_thread ?
(I'm writing a preprocessor and I do not want to use threads, so why would I have to link with boost_thread and pthread ?)
Wave drags in threads only if it gets compiled in an environment requiring threads (BOOST_HAS_THREADS is defined). If you build Wave such that BOOST_HAS_THREADS is not defined, it won't depend on threads.
But having threads and using threads are not the same thing ! Also, I find this configuration-based approach a little too coarse-grained. Ideally the question of whether or not to use threads (or whatever it is boost.spirit uses that requires thread support) would be configured using a template parameter (policy / traits), so the same library could be used with and without threads without requiring a separate build. Of course, this is all wishfull thinking only, I don't know boost.spirit and thus have no idea why you chose to design it the way you did. Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...