How to store the PxFixedJoint class in a vector

I'm trying to store the PxFixedJoint class in a std::vector with the push_back method. But the vector is always empty, it just does not add anything.

Down the code.

// C++
// Declaração do vector para armazenar os joints
std::vector<physx::PxFixedJoint*> m_lpJoints;

// Criando um joint
physx::PxFixedJoint* joint = physx::PxFixedJointCreate(*physics, m_pPhysicsBody, physx::PxTransform(-offset), _target, physx::PxTransform(offset));

// Armazenando
m_lpJoints.push_back(joint);

// Verificando o tamanho do vetor
std::cout << "size: " << m_lpJoints.size() << std::endl;