Leo Liberti wrote:

could anyone please tell me how to convert a cl_F to a double? I would like to write something like

cl_F var = 1.0; double d = var;

but the error is "`class cln::cl_F' used where a floating point value was expected".

Try double d = double_approx (var); As the name indicates, this returns an approximation, because it loses precision beyond the 16th decimal digit. Bruno