hpx_0.9.99 out of project build fails

[npezolano]

env

• Ubuntu 64bit 4.2.0-42-generic
  

• gcc version 5.2.1
  

• hpx 0.9.99
  

• boost 0.16.0
  

The HPX examples run fine but while building out of project the compiler is looking for C++14 functions

$ g++ main.cpp -I~/include -L~/lib -std=c++11 -o main
In file included from /home/n/git/cpp/libs/include/hpx/util/invoke_fused.hpp:13:0,
                 from /home/n/git/cpp/libs/include/hpx/util/bind.hpp:19,
                 from /home/n/git/cpp/libs/include/hpx/hpx_init_impl.hpp:16,
                 from /home/n/git/cpp/libs/include/hpx/hpx_init.hpp:716,
                 from main.cpp:1:
/home/n/git/cpp/libs/include/hpx/util/tuple.hpp:103:18: error: ‘is_final’ is not a member of ‘std’
              && !std::is_final<T>::value
                  ^
/home/n/git/cpp/libs/include/hpx/util/tuple.hpp:100:27: error: parse error in template argument list
             typename std::enable_if<
                           ^
/home/n/git/cpp/libs/include/hpx/util/tuple.hpp:105:13: error: template argument 3 is invalid
             >::type
             ^
/home/n/git/cpp/libs/include/hpx/util/tuple.hpp:106:9: error: expected unqualified-id before ‘>’ token
         > : T
         ^

Building main.cpp with -std=c++14 creates undefined reference errors:

/tmp/ccu3L4Wv.o: In function `(anonymous namespace)::check_hpx_version()':
main.cpp:(.text+0x1b): undefined reference to `hpx::hpx_check_version_0_9'
main.cpp:(.text+0x23): undefined reference to `hpx::hpx_check_boost_version_106100'
/tmp/ccu3L4Wv.o: In function `hpx_main(boost::program_options::variables_map&)':
main.cpp:(.text+0x4e): undefined reference to `hpx::throws'
/tmp/ccu3L4Wv.o: In function `__static_initialization_and_destruction_0(int, int)':
main.cpp:(.text+0x2da): undefined reference to `boost::system::generic_category()'
main.cpp:(.text+0x2e6): undefined reference to `boost::system::generic_category()'
main.cpp:(.text+0x2f2): undefined reference to `boost::system::system_category()'

[sithhell]

Could you give a little more detail please? What's your error? How did you configure your build?

[npezolano]

Sure sorry about that, I'm just trying to build a simple "hello world" program in my own project.

I built boost as follows:

./b2 -j32 --build-type=complete --layout=versioned toolset=gcc

for hpx:

cmake -DHPX_WITH_MALLOC=system \
      -DBOOST_ROOT=/home/n/git/cpp/libs \
      -DCMAKE_INSTALL_PREFIX=/home/n/git/cpp/libs \
      /home/n/git/cpp/downloads/hpx

I also tried adding cxxflags="-std=c++14" for boost and -DCMAKE_CXX_FLAGS="-std=c++14" for hpx and I get the same error when I compile in the first post.

[sithhell]

Ah, sorry for being dense. Your detailed description wasn't showing in my mail client.
First of all, yes, the c++ flavor chosen for hpx is probably not transparent enough...

Second, you need to link against the hpx libraries. You can either choose our cmake support our use pkg-config to get the correct settings. The docs are here:
http://stellar-group.github.io/hpx/docs/html/hpx/manual/build_system/using_hpx/pkgconfig.html

Does this fix your problem? Do you think the docs need to be extended to avoid future misunderstandings?

[hkaiser]

@npezolano This error happens whenever you build HPX with --std=c++14 (which is the default for any recent compiler) but your application is built using --std=c++11. You can enforce building HPX in C++11 mode by supplying -DHPX_WITH_CXX11=On to the cmake command line. Alternatively you can build your application using --std=c++14.

[npezolano]

@hkaiser @sithhell Thanks I was able to get it working, I can post a sample out of project build using Scons if it will help anyone.

[hkaiser]

Yes, please do! We could add that to the docs.