有没有办法根据构造函数的输入类型指定类成员的类型？

I am using a matrix library (Eigen) where the sizes of the matrices affect the type of the matrix. I am trying to create a class that is initialized with a constructor that takes a matrix and copies it over to the member matrix. Since this is a library, I would like to do this so that the user doesn't have to know the size of their matrix when they initialize my matrix class (because maybe their matrix is coming from another file) Basically I would like something like the code below, where I am using a matrix library (Eigen) where the s