I'm getting the following compilation error on the git master branch mpi py_nonblocking.cpp 

libs/mpi/src/python/py_nonblocking.cpp:166:14: error: no viable conversion from 'optional<(anonymous namespace)::py_call_output_iterator<boost::mpi::status, std::__1::__wrap_iter<boost::mpi::python::request_with_value *> > >' to 'bool'

      return test_all(requests.begin(), requests.end(), 

             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1 error generated.

when compiling with clang:

"clang++" -x c++ -Wl,-flat_namespace -stdlib=libc++ -nostdinc++ -std=c++1y -I/Users/gnzlbg/src/env/include/libcxx -O3 -O3 -finline-functions -Wno-inline -Wall -DBOOST_ALL_NO_LIB=1 -DBOOST_MPI_DYN_LINK=1 -DBOOST_MPI_PYTHON_DYN_LINK=1 -DBOOST_PYTHON_DYN_LINK=1 -DNDEBUG -I"." -I"/Users/gnzlbg/src/env/include" -I"/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/include/python2.7" -c -o "/Users/gnzlbg/src/env/boost_build/boost/bin.v2/libs/mpi/build/clang-darwin-4.2.1/release/threading-multi/python/py_nonblocking.o" "libs/mpi/src/python/py_nonblocking.cpp"

Any ideas?