C++ hierarchy and access to the outer class

I have a particle class which keeps the position, velocity and the acceleration of an object. I can access the related part of the vector via .position(), .velocity() and .acceleration(). I also can access each single number like .velocity_x(), .velocity_y(), .velocity_z() etc. what I would like to do is to access the z part of velocity this way:

p.velocity().z()

Is this implementation possible in c++?

#include <iostream>
#include <armadillo>

class Particle
{
public:
    arma::vec::fixed<9> data;

    inline double velocity_z() const
    {
        return data(5);
    }
    inline double& velocity_z()
    {
        return data(5);
    }

    inline const arma::subview_col<double> position() const
    {
        return data.subvec(0,2);
    }
    inline arma::subview_col<double> position()
    {
        return data.subvec(0,2);
    }
    inline const arma::subview_col<double> velocity() const
    {
        return data.subvec(3,5);
    }
    inline arma::subview_col<double> velocity()
    {
        return data.subvec(3,5);
    }
    inline const arma::subview_col<double> acceleration() const
    {
        return data.subvec(6,8);
    }
    inline arma::subview_col<double> acceleration()
    {
        return data.subvec(6,8);
    }
};

arma::vec vector3(double x,double y,double z)
{
    return {x,y,z};
}

int main()
{
    Particle p;
    p.position()=vector3(1.1,2.1,3.1);
    p.velocity()=vector3(1.2,2.2,3.2);
    p.velocity_z()=10.0;
    p.acceleration()=vector3(1.3,2.3,3.3);
    p.data.print();
    return 0;
}


// output:

//     1.1000
//     2.1000
//     3.1000
//     1.2000
//     2.2000
//    10.0000
//     1.3000
//     2.3000
//     3.3000

make:

g++ -std=c++11 test1.cpp -larmadillo

link to armadillo documentation

update

I would like to use both .velocity() (as a subvector) and .velocity().z() (as a single number) at the same time.

I also would like to avoid defining any extra variable. I prefer everything be interpreted at the compile time (due to performance priority).