Ubuntu16.04下编译ORB_SLAM2错误

到Ubuntu16.04下编译ORB_SLAM2报错，提示：

/usr/include/eigen3/Eigen/src/Core/AssignEvaluator.h:745:3: error: static assertion failed:YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY
　　EIGEN_CHECK_BINARY_COMPATIBILIY(Func,typename ActualDstTypeCleaned::Scalar,typename Src::Scalar);

/usr/include/eigen3/Eigen/src/Core/AssignEvaluator.h: In instantiation of ‘void Eigen::internal::call_assignment_no_alias(Dst&, const Src&, const Func&) [with Dst = Eigen::Matrix; Src = Eigen::Matrix; Func = Eigen::internal::assign_op]’:
/usr/include/eigen3/Eigen/src/Core/AssignEvaluator.h:712:27:   required from ‘void Eigen::internal::call_assignment(Dst&, const Src&, const Func&, typename Eigen::internal::enable_if<(! Eigen::internal::evaluator_assume_aliasing::value), void*>::type) [with Dst = Eigen::Matrix; Src = Eigen::Matrix; Func = Eigen::internal::assign_op; typename Eigen::internal::enable_if<(! Eigen::internal::evaluator_assume_aliasing::value), void*>::type = void*]’
/usr/include/eigen3/Eigen/src/Core/AssignEvaluator.h:693:18:   required from ‘void Eigen::internal::call_assignment(Dst&, const Src&) [with Dst = Eigen::Matrix; Src = Eigen::Matrix]’
/usr/include/eigen3/Eigen/src/Core/PlainObjectBase.h:682:32:   required from ‘Derived& Eigen::PlainObjectBase::_set(const Eigen::DenseBase&) [with OtherDerived = Eigen::Matrix; Derived = Eigen::Matrix]’
/usr/include/eigen3/Eigen/src/Core/Matrix.h:225:24:   required from ‘Eigen::Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols>& Eigen::Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols>::operator=(const Eigen::DenseBase&) [with OtherDerived = Eigen::Matrix; _Scalar = int; int _Rows = -1; int _Cols = 1; int _Options = 0; int _MaxRows = -1; int _MaxCols = 1]’
/usr/include/eigen3/Eigen/src/Core/PermutationMatrix.h:367:17:   required from ‘Eigen::PermutationMatrix& Eigen::PermutationMatrix::operator=(const Eigen::PermutationBase&) [with Other = Eigen::PermutationMatrix<-1, -1, long int>; int SizeAtCompileTime = -1; int MaxSizeAtCompileTime = -1; _StorageIndex = int]’
/home/armmlinux/zdfwork/work/SLAM/orb_slam/ORB_SLAM2-master/Thirdparty/g2o/g2o/solvers/linear_solver_eigen.h:68:18:   required from ‘void g2o::LinearSolverEigen::CholeskyDecomposition::analyzePatternWithPermutation(g2o::LinearSolverEigen::SparseMatrix&, const PermutationMatrix&) [with MatrixType = Eigen::Matrix; g2o::LinearSolverEigen::SparseMatrix = Eigen::SparseMatrix; g2o::LinearSolverEigen::PermutationMatrix = Eigen::PermutationMatrix<-1, -1, long int>]’
/home/armmlinux/zdfwork/work/SLAM/orb_slam/ORB_SLAM2-master/Thirdparty/g2o/g2o/solvers/linear_solver_eigen.h:195:9:   required from ‘void g2o::LinearSolverEigen::computeSymbolicDecomposition(const g2o::SparseBlockMatrix&) [with MatrixType = Eigen::Matrix]’
/home/armmlinux/zdfwork/work/SLAM/orb_slam/ORB_SLAM2-master/Thirdparty/g2o/g2o/solvers/linear_solver_eigen.h:100:37:   required from ‘bool g2o::LinearSolverEigen::solve(const g2o::SparseBlockMatrix&, double*, double*) [with MatrixType = Eigen::Matrix]’
/home/armmlinux/zdfwork/work/SLAM/orb_slam/ORB_SLAM2-master/src/Optimizer.cc:1244:1:   required from here
/usr/include/eigen3/Eigen/src/Core/util/StaticAssert.h:32:40: error: static assertion failed: YOU_MIXED_DIFFERENT_NUMERIC_TYPES__YOU_NEED_TO_USE_THE_CAST_METHOD_OF_MATRIXBASE_TO_CAST_NUMERIC_TYPES_EXPLICITLY
     #define EIGEN_STATIC_ASSERT(X,MSG) static_assert(X,#MSG);
                                        ^
/usr/include/eigen3/Eigen/src/Core/util/XprHelper.h:707:3: note: in expansion of macro ‘EIGEN_STATIC_ASSERT’
   EIGEN_STATIC_ASSERT((internal::functor_is_product_like::ret \
   ^
/usr/include/eigen3/Eigen/src/Core/AssignEvaluator.h:745:3: note: in expansion of macro ‘EIGEN_CHECK_BINARY_COMPATIBILIY’
   EIGEN_CHECK_BINARY_COMPATIBILIY(Func,typename ActualDstTypeCleaned::Scalar,typename Src::Scalar);
   ^
CMakeFiles/ORB_SLAM2.dir/build.make:350: recipe for target 'CMakeFiles/ORB_SLAM2.dir/src/Optimizer.cc.o' failed
make[2]: *** [CMakeFiles/ORB_SLAM2.dir/src/Optimizer.cc.o] Error 1
CMakeFiles/Makefile2:178: recipe for target 'CMakeFiles/ORB_SLAM2.dir/all' failed
make[1]: *** [CMakeFiles/ORB_SLAM2.dir/all] Error 2
Makefile:83: recipe for target 'all' failed

make: *** [all] Error 2

问题原因：Eigen3的bug

解决方法： 打开Thirdparty/g2o/g2o/solvers/linear_solver_eigen.h，将以下代码

1 template 
2 class LinearSolverEigen: public LinearSolver
3 {
4   public:
5     typedef Eigen::SparseMatrix<double, Eigen::ColMajor> SparseMatrix;
6     typedef Eigen::Triplet<double> Triplet;
7     typedef Eigen::PermutationMatrixSparseMatrix::Index> PermutationMatrix;

改为

1 template 
2 class LinearSolverEigen: public LinearSolver
3 {
4   public:
5     typedef Eigen::SparseMatrix<double, Eigen::ColMajor> SparseMatrix;
6     typedef Eigen::Triplet<double> Triplet;
8     typedef Eigen::PermutationMatrixint> PermutationMatrix;
9     /**