http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53455
--- Comment #12 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-06-14 12:51:08 UTC --- Maybe someone should look at fixing these warnings in Boost.Python, or ensure -fno-strict-aliasing is used "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -m64 -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/apps/infra/3rd-party/gcc-4.4-64/python-2.6.5/include/python2.6" -c -o "bin.v2/libs/python/build/gcc-4.7.0/release/threading-multi/object/enum.o" "libs/python/src/object/enum.cpp" libs/python/src/object/enum.cpp: In function 'boost::python::api::object boost::python::objects::{anonymous}::new_enum_type(const char*, const char*)': libs/python/src/object/enum.cpp:150:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -m64 -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/apps/infra/3rd-party/gcc-4.4-64/python-2.6.5/include/python2.6" -c -o "bin.v2/libs/python/build/gcc-4.7.0/release/threading-multi/object/class.o" "libs/python/src/object/class.cpp" libs/python/src/object/class.cpp: In function 'PyObject* boost::python::objects::static_data()': libs/python/src/object/class.cpp:211:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] libs/python/src/object/class.cpp: In function 'boost::python::type_handle boost::python::objects::class_metatype()': libs/python/src/object/class.cpp:319:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] libs/python/src/object/class.cpp: In function 'boost::python::type_handle boost::python::objects::class_type()': libs/python/src/object/class.cpp:473:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] gcc.compile.c++ bin.v2/libs/python/build/gcc-4.7.0/release/threading-multi/object/life_support.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -m64 -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/apps/infra/3rd-party/gcc-4.4-64/python-2.6.5/include/python2.6" -c -o "bin.v2/libs/python/build/gcc-4.7.0/release/threading-multi/object/life_support.o" "libs/python/src/object/life_support.cpp" libs/python/src/object/life_support.cpp: In function 'PyObject* boost::python::objects::make_nurse_and_patient(PyObject*, PyObject*)': libs/python/src/object/life_support.cpp:94:9: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] libs/python/src/object/life_support.cpp:96:9: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] gcc.compile.c++ bin.v2/libs/python/build/gcc-4.7.0/release/threading-multi/object/function.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -m64 -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/apps/infra/3rd-party/gcc-4.4-64/python-2.6.5/include/python2.6" -c -o "bin.v2/libs/python/build/gcc-4.7.0/release/threading-multi/object/function.o" "libs/python/src/object/function.cpp" libs/python/src/object/function.cpp: In constructor 'boost::python::objects::function::function(const boost::python::objects::py_function&, const boost::python::detail::keyword*, unsigned int)': libs/python/src/object/function.cpp:108:9: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] libs/python/src/object/function.cpp:110:9: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]