multi-definition error if build static libraries

[CanCanZeng]

Hi, I build maplab (develop branch 483daf4) successfully on ubuntu16.04 and ubuntu20.04 under the guide of documents. But when I add some flag in compilation, catkin config --cmake-args -DBUILD_SHARED_LIBS=0 , there are some multi-definition error.

I figured out these problems and I would like to share the method(report maybe two bugs)

1.

the matching-based-engine.h includes matching-based-engine-inl.h here

maplab/algorithms/loopclosure/matching-based-loopclosure/include/matching-based-loopclosure/matching-based-engine.h

Line 133 in 483daf4

#include "./matching-based-engine-inl.h"

, and matching-based-engine-inl.h includes matching-based-engine.h here

maplab/algorithms/loopclosure/matching-based-loopclosure/include/matching-based-loopclosure/matching-based-engine-inl.h

Line 14 in 483daf4

#include "matching-based-loopclosure/matching-based-engine.h"

, this can be fixed by including matching-based-engine-inl.h in matching-based-engine.cc

2. (maybe this problem should be reported under https://github.com/ethz-asl/aslam_cv2 , but I think report in here is OK)

you implement GyroTwoFrameMatcher::getKeypointIteratorsInWindow in .h file here https://github.com/ethz-asl/aslam_cv2/blob/a385593ccc6c4d0dcead618581817d203afc5d11/aslam_cv_matcher/include/aslam/matcher/gyro-two-frame-matcher.h#L196 , and includes gyro-two-frame-matcher.h file in both https://github.com/ethz-asl/aslam_cv2/blob/a385593ccc6c4d0dcead618581817d203afc5d11/aslam_cv_matcher/src/gyro-two-frame-matcher.cc#L1 and https://github.com/ethz-asl/aslam_cv2/blob/a385593ccc6c4d0dcead618581817d203afc5d11/aslam_cv_tracker/src/feature-tracker-gyro.cc#L8 , but both aslam_cv_matcher module and aslam_cv_tracker module are used by rovioli, so this will cause multi-definition. this can be fixed by moving the implementation of GyroTwoFrameMatcher::getKeypointIteratorsInWindow to gyro-two-frame-matcher.cc