clang-tidy -checks=-*,modernize-use-nullptr

extern/lodepng/lodepng.cpp

src/blockforest/GlobalLoadBalancing.h

src/boundary/BoundaryHandling.h

src/core/Array.h

src/core/math/extern/exprtk.h

src/domain_decomposition/BlockStorage.h

src/domain_decomposition/IBlock.h

src/field/Field.impl.h

src/field/FieldClone.h

src/field/vtk/FlagFieldMapping.h

src/geometry/containment_octree/BranchNode.h

src/lbm/PerformanceEvaluation.h

src/lbm/boundary/DiffusionDirichlet.h

src/lbm/boundary/ParserUBB.h

src/lbm/boundary/Pressure.h

src/lbm/boundary/VelocityBoundary.h

src/lbm/field/DensityVelocityCallback.h

src/lbm/lattice_model/ForceModel.h

src/lbm/sweeps/ActiveCellSweep.h

src/lbm/sweeps/CellwiseSweep.h