Include of boost have to be the first

[razerraz]

Building python extension on ARM fails. Moving include of boost library on top of the file solve the issue :

gcc -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16 -O3 -pipe -fno-plt -fno-semantic-interposition -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16 -O3 -pipe -fno-plt -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16 -O3 -pipe -fno-plt -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16 -O2 -pipe -fstack-protector-strong -fno-plt -marm -march=armv6zk -mtune=arm1176jzf-s -mfpu=vfp -mfloat-abi=hard -L/usr/lib -I/usr/include -D_FORTIFY_SOURCE=2 -fPIC -I/usr/include/python3.9 -c pyRF24.cpp -o build/temp.linux-armv7l-3.9/pyRF24.o
In file included from /usr/include/boost/python/detail/def_helper.hpp:16,
                 from /usr/include/boost/python/class.hpp:29,
                 from /usr/include/boost/python.hpp:18,
                 from pyRF24.cpp:2:
/usr/include/boost/tuple/tuple.hpp:87:70: error: template argument 1 is invalid
   87 | template<class H, class T> class tuple_size< boost::tuples::cons<H, T> >:
      |                                                                      ^
/usr/include/boost/tuple/tuple.hpp:87:72: error: template argument 1 is invalid
   87 | template<class H, class T> class tuple_size< boost::tuples::cons<H, T> >:
      |                                                                        ^
/usr/include/boost/tuple/tuple.hpp:88:59: error: template argument 1 is invalid
   88 |     public boost::tuples::length< boost::tuples::cons<H, T> >
      |                                                           ^
/usr/include/boost/tuple/tuple.hpp:88:61: error: template argument 1 is invalid
   88 |     public boost::tuples::length< boost::tuples::cons<H, T> >
      |                                                             ^
/usr/include/boost/tuple/tuple.hpp:105:91: error: template argument 1 is invalid
  105 | template<std::size_t I, class H, class T> class tuple_element< I, boost::tuples::cons<H, T> >:
      |                                                                                           ^
/usr/include/boost/tuple/tuple.hpp:105:93: error: template argument 2 is invalid
  105 | template<std::size_t I, class H, class T> class tuple_element< I, boost::tuples::cons<H, T> >:
      |                                                                                             ^
/usr/include/boost/tuple/tuple.hpp:106:63: error: template argument 1 is invalid
  106 |     public boost::tuples::element< I, boost::tuples::cons<H, T> >
      |                                                               ^
/usr/include/boost/tuple/tuple.hpp:106:65: error: template argument 2 is invalid
  106 |     public boost::tuples::element< I, boost::tuples::cons<H, T> >
      |                                                                 ^
In file included from /usr/include/boost/smart_ptr/detail/sp_thread_sleep.hpp:22,
                 from /usr/include/boost/smart_ptr/detail/yield_k.hpp:23,
                 from /usr/include/boost/smart_ptr/detail/spinlock_gcc_atomic.hpp:14,
                 from /usr/include/boost/smart_ptr/detail/spinlock.hpp:42,
                 from /usr/include/boost/smart_ptr/detail/spinlock_pool.hpp:25,
                 from /usr/include/boost/smart_ptr/shared_ptr.hpp:29,
                 from /usr/include/boost/shared_ptr.hpp:17,
                 from /usr/include/boost/python/converter/shared_ptr_to_python.hpp:12,
                 from /usr/include/boost/python/converter/arg_to_python.hpp:15,
                 from /usr/include/boost/python/call.hpp:15,
                 from /usr/include/boost/python/object_core.hpp:14,
                 from /usr/include/boost/python/args.hpp:22,
                 from /usr/include/boost/python.hpp:11,
                 from pyRF24.cpp:2:

Archlinux on Raspberry pi 3 - python 3.9 - gcc 10.2.0 - boost 1.75

[2bndy5]

FYI

Currently the Linux CI action reports using

gcc version 7.5.0 (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04) 
Python 3.6.9

IIRC, last I checked Raspbian (now Rasbperry Pi OS) installs libboost v1.69. Also, libboost v1.70+ dropped python 2 support.

I don't know what version of gcc will be installed by apt-get when GitHub actions switch to using Ubuntu 20.04 as ubuntu-latest

[razerraz]

Well, I don't know the code enough to be sure this can't lead to regressions.
Anyway archlinux AUR package has been patched by myself and builds fine now, there is no hurry then.

[2bndy5]

Anyway archlinux AUR package has been patched by myself and builds fine now

@razerraz does that mean that this is still needed on our end? It feels like this change isn't really necessary here. Nothing in the RF24 C++ source depends on boost.python (only the pyRF24.cpp file in question).

[razerraz]

@razerraz does that mean that this is still needed on our end?

Yes it's still needed for building 1.4.1

[2bndy5]

I recently found this solved building with pybind11 also

[razerraz]

Thanks a lot, life is easier without one patch to maintain