Hello, I have a problem when compiling code using boost::interprocess library code. I've run into a compile error while trying to create a map in a boost shared memory object. I am using the VisualStudio2005 C++ compiler, and boost 1.38. The symptom is: C:\svn\ThirdPartySDK\boost_1_38_0\boost/interprocess/containers/map.hpp( 140) : error C2512: 'boost::interprocess::allocator<T,SegmentManager>::allocator' : no appropriate default constructor available with [ T=std::pair<sage::lib::clientDataServer::MapKey<10>,sage::lib::clientDat aServer::Data>, SegmentManager=boost::interprocess::segment_manager<char,boost::interpro cess::rbtree_best_fit<boost::interprocess::mutex_family>,boost::interpro cess::iset_index> ] Quick description - code is attached below: templated class ReadOnlyCatalog, taking an int template LENGTH and a template parm class T (T is the mapped data, or "second" in the pair). the map index is a templated class called MapKey, taking an int LENGTH. templated class MapKeyLess to provide the less() operator for the map index. Can anyone tell why am I getting the compiler error? Your help is greatly appreciated. template <int LENGTH, class T> class ReadOnlyCatalog { public: typedef std::pair<MapKey<LENGTH>, T> Value_t; typedef boost::interprocess::allocator<Value_t, boost::interprocess::managed_shared_memory::segment_manager> Allocator_t; typedef boost::interprocess::map<MapKey<LENGTH>, T, MapKeyLess<LENGTH>, Allocator_t> Map_t; ReadOnlyCatalog() { ... } ReadOnlyCatalog( const RoShMemType_e in_type, const std::string& in_segName, const std::string& in_objName ) { ... } }; const int OrderTypeKeyLength = 10; class Data { public: Data() { ... }; } template <int LENGTH> class MapKey { public: MapKey() { .. } MapKey( const std::string& in_key ) { ... } public: char m_key[LENGTH + 1]; }; template <int LENGTH> class MapKeyLess { public: bool operator()( const MapKey<LENGTH>& a, const MapKey<LENGTH>& b ) const { return strncmp( a.m_key, b.m_key, LENGTH ) < 0; } }; // instantiate ReadOnlyCatalog template; class OrderTypeCatalog : public ReadOnlyCatalog<OrderTypeKeyLength, Data> { public: OrderTypeCatalog() {} OrderTypeCatalog( const RoShMemType_e in_type, const std::string& in_segName, const std::string& in_objName ) : ReadOnlyCatalog( in_type, in_segName, in_objName ) {}; }; // a use of OrderTypeCatalog class X { public: X() { ptr = new OrderTypeCatalog( in_type, "aaa", "bbb" ); } private: OrderTypeCatalog* ptr; }; Included headers: #include <boost/interprocess/shared_memory_object.hpp> #include <boost/interprocess/mapped_region.hpp> #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/interprocess/allocators/allocator.hpp> Full compiler error message: C:\svn\ThirdPartySDK\boost_1_38_0\boost/interprocess/containers/map.hpp( 140) : error C2512: 'boost::interprocess::allocator<T,SegmentManager>::allocator' : no appropriate default constructor available with [ T=std::pair<sage::lib::clientDataServer::MapKey<10>,sage::lib::clientDat aServer::Data>, SegmentManager=boost::interprocess::segment_manager<char,boost::interpro cess::rbtree_best_fit<boost::interprocess::mutex_family>,boost::interpro cess::iset_index> ] C:\svn\Projects\trunk\Lib/ClientDataServer/ReadOnlySegments.h(166) : while compiling class template member function 'sage::lib::clientDataServer::ReadOnlyCatalog<LENGTH,T>::ReadOnlyCatalog (void)' with [ LENGTH=10, T=sage::lib::clientDataServer::Data ] C:\svn\Projects\trunk\Lib/CLientDataServer/ReadOnlyShMem.h(25) : see reference to class template instantiation 'sage::lib::clientDataServer::ReadOnlyCatalog<LENGTH,T>' being compiled with [ LENGTH=10, T=sage::lib::clientDataServer::Data ] Regards, Chris Miclea