Fix some more clang-tidy suggestions. Change-Id: Ic4bb725df1e0b49f2e14c889136433841d98ae22
Ceres Solver is an open source C++ library for modeling and solving large, complicated optimization problems. It is a feature rich, mature and performant library which has been used in production at Google since 2010. Ceres Solver can solve two kinds of problems.
Please see ceres-solver.org for more information.