/** @page dev-roadmap Future Roadmap The initial release provides the library foundation which contains a filter-based visual-inertial localization solution. This can be used in a wide range of scenarios and the type-based index system allows for others to easily add new features and develop on top of this system. Here is a list of future directions, although nothing is set in stone, that we are interested in taking: - Creation of a secondary graph-based thread that loosely introduces loop closures (akin to the second thread of VINS-Mono and others) which should allow for drift free long-term localization. - Large scale offline batch graph optimization which leverages the trajectory of the ov_msckf as its initial guess and then optimizes both the map and trajectory. - Incorporate our prior work in preintegration @cite Eckenhoff2019IJRR into the same framework structure to allow for easy extensibility. Focus on sparsification and marginalization to allow for realtime computation. - Leverage this sliding-window batch method to perform SFM initialization of all methods. - Support for arbitrary Schmidt'ing of state elements allowing for modeling of their prior uncertainties but without optimizing their values online. - More advance imu integration schemes, quantification of the integration noises to handle low frequency readings, and modeling of the imu intrinsics. */