Hello, global logger declaration as follows BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(mylog_master, boost::log::sources::severity_loggerboost::log::trivial::severity_level); issues a lots of warnings (see below) pointing to some smart_ptr code. If anyone could advice - does it look like my problem or something else – it would be greatly appreciated. Cheers, Valerii. Warning text: In file included from /usr/local/boost-1.55.0/include/boost/smart_ptr/make_shared_object.hpp:17, from /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:21, from /usr/local/boost-1.55.0/include/boost/log/common.hpp:24, from mylog.cpp:10: /usr/local/boost-1.55.0/include/boost/smart_ptr/detail/sp_forward.hpp: In function ‘T&& boost::detail::sp_forward(T&) [with T = const char*]’: /usr/local/boost-1.55.0/include/boost/smart_ptr/make_shared_object.hpp:218: instantiated from ‘typename boost::detail::sp_if_not_array<T>::type boost::make_shared(Arg1&&, Args&& ...) [with T = boost::log::v2s_mt_posix::sources::aux::logger_holderboost::log::v2s_mt_posix::trivial::severity_level >, Arg1 = const char*, Args = unsigned int, mylog_master::logger_type]’ /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:141: instantiated from ‘static boost::shared_ptrboost::log::v2s_mt_posix::sources::aux::logger_holder_base boost::log::v2s_mt_posix::sources::aux::logger_singleton<TagT>::construct_logger() [with TagT = mylog_master]’ /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:121: instantiated from ‘static void boost::log::v2s_mt_posix::sources::aux::logger_singleton<TagT>::init_instance() [with TagT = mylog_master]’ /usr/local/boost-1.55.0/include/boost/log/detail/singleton.hpp:45: instantiated from ‘static StorageT& boost::log::v2s_mt_posix::aux::lazy_singleton::get() [with DerivedT = boost::log::v2s_mt_posix::sources::aux::logger_singleton, StorageT = boost::shared_ptrboost::log::v2s_mt_posix::trivial::severity_level > >]’ /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:112: instantiated from ‘static typename TagT::logger_type& boost::log::v2s_mt_posix::sources::aux::logger_singleton<TagT>::get() [with TagT = mylog_master]’ ../../include/myproject/mylog.hpp:20: instantiated from here /usr/local/boost-1.55.0/include/boost/smart_ptr/detail/sp_forward.hpp:30: warning: returning reference to temporary mylog.hpp:20 is the line where global logger is declared: BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(mylog_master, boost::log::sources::severity_loggerboost::log::trivial::severity_level); And my platform / compiler: $ gcc -v Using built-in specs. Target: x86_64-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 4.4.7 20120313 (Red Hat 4.4.7-3) (GCC)