Thread: vector of object inside object not getting populated

I have two class Particle and Spring.

Spring:

Code:

classSpring{
private:
    double ks;
    double kd;
    double l0;
    int orig, dest;

public:
    Spring(int from, int to, double spring_const);
    glm::vec3 calculate_spring_force(glm::vec3 xa, glm::vec3 xb, double mass, glm::vec3 velocity);

};

Particle:

Code:

class Particle
{
private:
    glm::vec3 position;
    glm::vec3 velocity;
    glm::vec3 total_force;
    std::vector<Spring> springs;
    double mass;
    bool fixed;

public:
    Particle(glm::vec3 pos);
    void add_spring(int from, int to, double spring_const);
    glm::vec3 get_position()
    {
        return position;
    }
    int get_spring_count()
    {
        springs.size();
    }
};


void Particle::add_spring(int from, int to, double spring_const)
{
    springs.push_back(Spring(from, to, spring_const));
}

I need to have a vector of particles. And each particle can contain many springs.

When I am populating the particles and springs inside main()

Code:

std::vector<Particle> particles;
int particle_count = 0;
for (size_t i = 0; i < n; i++)
{
    for (size_t j = 0; j < n; j++)
    {
        Particle particle(particle_positions[particle_count]);

        for (size_t k = 0; k < conn.cols(); k++)
        {
            if (some_func(particle_count, k))
            {
                particle.add_spring(particle_count, k, conn(particle_count, k));
            }
        }
        particles.push_back(particle);
        particle_count++;
    }
}

I expected to see many springs inside each particle but I see that each particle has 0 spring.I have checked every other functions and they are doing their job fine.

Springs are not getting populated for some reason.
I urge this respected community to look into this issue.