id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc 12450,oost/serialization/singleton.hpp:131: undefined reference to `boost::serialization::singleton_module::is_locked()',NASa Qian ,Robert Ramey,"When I am using the and compile my code, there is an error: oost/serialization/singleton.hpp:131: undefined reference to `boost::serialization::singleton_module::is_locked()' I find the body of member functions of singleton_module is removed since version 1.61.0. Since user use only hpp file to inlucde and compile, so please reset the code as the pervious version such as 1.60 and 1.59",Bugs,new,Boost 1.63.0,serialization,Boost 1.61.0,Regression,,singleton_module serialization wserialization,