Maybe it could be better if I let you see the error log: // Compiled with /W0 //begin log w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2825: 'boost::random::detail::pass_through_engine::base_type': must be a class or namespace when followed by '::' with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0\boost\random\uniform_01.hpp(80) : see reference to class template instantiation 'boost::random::detail::pass_through_engine' being compiled with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0\boost\random\lagged_fibonacci.hpp(301) : see reference to class template instantiation 'boost::uniform_01' being compiled with [ UniformRandomNumberGenerator=ref_gen, RealType=double ] c:\documents and settings\gabriele\documenti\visual studio 2005 \projects\nanosynthetic flares - consoleapp\nanosynthetic flares - consoleapp\random_inlines.h(20) : see reference to function template instantiation 'void boost::random::lagged_fibonacci_01::seed(Generator &)' being compiled with [ RealType=double, w=48, p=19937, q=9842, Generator=unsigned int ] w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2039: 'result_type' : is not a member of '`global namespace'' w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2146: syntax error : missing ';' before identifier 'result_type' w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2602: 'boost::random::detail::pass_through_engine::result_type' is not a member of a base class of 'boost::random::detail::pass_through_engine' with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0 \boost\random\detail\pass_through_engine.hpp(33) : see declaration of 'boost::random::detail::pass_through_engine::result_type' with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2868: 'boost::random::detail::pass_through_engine::result_type' : illegal syntax for using-declaration; expected qualified-name with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2825: 'boost::random::detail::pass_through_engine::base_type': must be a class or namespace when followed by '::' with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0\boost\random\uniform_01.hpp(80) : see reference to class template instantiation 'boost::random::detail::pass_through_engine' being compiled with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0\boost\random\lagged_fibonacci.hpp(301) : see reference to class template instantiation 'boost::uniform_01' being compiled with [ UniformRandomNumberGenerator=ref_gen, RealType=double ] c:\documents and settings\gabriele\documenti\visual studio 2005 \projects\nanosynthetic flares - consoleapp\nanosynthetic flares - consoleapp\random_inlines.h(20) : see reference to function template instantiation 'void boost::random::lagged_fibonacci_01::seed(Generator &)' being compiled with [ RealType=double, w=48, p=19937, q=9842, Generator=unsigned int ] w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2039: 'result_type' : is not a member of '`global namespace'' w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2146: syntax error : missing ';' before identifier 'result_type' w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2602: 'boost::random::detail::pass_through_engine::result_type' is not a member of a base class of 'boost::random::detail::pass_through_engine' with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0 \boost\random\detail\pass_through_engine.hpp(33) : see declaration of 'boost::random::detail::pass_through_engine::result_type' with [ UniformRandomNumberGenerator=unsigned int & ] w:\boost c++ libraries 1.34.0\boost\random\detail\pass_through_engine.hpp (33) : error C2868: 'boost::random::detail::pass_through_engine::result_type' : illegal syntax for using-declaration; expected qualified-name with [ UniformRandomNumberGenerator=unsigned int & ] //end log Hope this could help you in helping me... Thanks, Gabriele