Make ConditionedCostFunction compatible with repeated CostFunction. If the user uses the same conditioner twice, it does not lead to a double free errors. https://github.com/ceres-solver/ceres-solver/issues/422 Change-Id: I9041ddcbffa8dcb882a63bddb82b384897efc970
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.