template struct RotationalPart<sophus::SO2d>ΒΆ
template <> struct RotationalPart<sophus::SO2d> { // methods static double norm(const typename sophus::SO2d::Tangent& t); };
template <> struct RotationalPart<sophus::SO2d> { // methods static double norm(const typename sophus::SO2d::Tangent& t); };