I am a fresh new user ( I need to extend some EIGEN library feature by using your float128 ) How to assign a "float128" variable with a regular "double" variable ? With my source code in attachement double double_pi = 3.141592653589793 ; float128 float128_pi = 3.141592653589793Q ; produces the output that looks fine to me double_pi = 3.141592653589793e+00 float128_pi = 3.141592653589793000000000000000000e+00 but thestatement float128_pi = double_pi ; produces float128_pi = 3.141592653589793115997963468544185e+00 How to get 3.141592653589793000000000000000000e+00 also from an assigment ??? What am I doing wrong ? Thanks for any help Regards, Jacques