Hello, I had a slight problem compiling random_demo.cpp after I had changed the typedef to: typedef boost::mt19937 base_generator_type; I got this error: --------------------Configuration: random_demo - Win32 Debug-------------------- Compiling... random_demo.cpp d:\c_plus_plus\boost_1_29_0\boost\random\mersenne_twister.hpp(104) : error C2064: term does not evaluate to a function d:\c_plus_plus\boost_1_29_0\boost\random\mersenne_twister.hpp(75) : see reference to function template instantiation 'void __thiscall boost::random::mersenne_twister::seed(const unsigned int &)' being compiled Error executing cl.exe. Creating browse info file... random_demo.exe - 1 error(s), 0 warning(s) I fixed it by adding an 'L' to the first line of main, i.e. base_generator_type generator(42Lu);