Remove const from return-by-value types (issue #1087)

libeigen/eigen!2144 Closes #1087 Co-authored-by: Rasmus Munk Larsen <rmlarsen@gmail.com>
2026-04-10 11:34:33 +08:00 · 2026-02-18 03:10:11 -08:00
parent 3108f6360e
commit bdec88009d
22 changed files with 123 additions and 128 deletions
--- a/Eigen/src/Cholesky/LDLT.h
+++ b/Eigen/src/Cholesky/LDLT.h
@@ -203,7 +203,7 @@ class LDLT : public SolverBase<LDLT<MatrixType_, UpLo_> > {
   * \sa MatrixBase::ldlt(), SelfAdjointView::ldlt()
   */
  template <typename Rhs>
-  inline const Solve<LDLT, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<LDLT, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  template <typename Derived>
@@ -642,8 +642,8 @@ MatrixType LDLT<MatrixType, UpLo_>::reconstructedMatrix() const {
 * \sa MatrixBase::ldlt()
 */
 template <typename MatrixType, unsigned int UpLo>
-inline const LDLT<typename SelfAdjointView<MatrixType, UpLo>::PlainObject, UpLo>
-SelfAdjointView<MatrixType, UpLo>::ldlt() const {
+inline LDLT<typename SelfAdjointView<MatrixType, UpLo>::PlainObject, UpLo> SelfAdjointView<MatrixType, UpLo>::ldlt()
+    const {
  return LDLT<PlainObject, UpLo>(m_matrix);
 }

@@ -652,7 +652,7 @@ SelfAdjointView<MatrixType, UpLo>::ldlt() const {
 * \sa SelfAdjointView::ldlt()
 */
 template <typename Derived>
-inline const LDLT<typename MatrixBase<Derived>::PlainObject> MatrixBase<Derived>::ldlt() const {
+inline LDLT<typename MatrixBase<Derived>::PlainObject> MatrixBase<Derived>::ldlt() const {
  return LDLT<PlainObject>(derived());
 }

--- a/Eigen/src/Cholesky/LLT.h
+++ b/Eigen/src/Cholesky/LLT.h
@@ -139,7 +139,7 @@ class LLT : public SolverBase<LLT<MatrixType_, UpLo_> > {
   * \sa solveInPlace(), MatrixBase::llt(), SelfAdjointView::llt()
   */
  template <typename Rhs>
-  inline const Solve<LLT, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<LLT, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  template <typename Derived>
@@ -497,7 +497,7 @@ MatrixType LLT<MatrixType, UpLo_>::reconstructedMatrix() const {
 * \sa SelfAdjointView::llt()
 */
 template <typename Derived>
-inline const LLT<typename MatrixBase<Derived>::PlainObject> MatrixBase<Derived>::llt() const {
+inline LLT<typename MatrixBase<Derived>::PlainObject> MatrixBase<Derived>::llt() const {
  return LLT<PlainObject>(derived());
 }

@@ -506,7 +506,7 @@ inline const LLT<typename MatrixBase<Derived>::PlainObject> MatrixBase<Derived>:
 * \sa SelfAdjointView::llt()
 */
 template <typename MatrixType, unsigned int UpLo>
-inline const LLT<typename SelfAdjointView<MatrixType, UpLo>::PlainObject, UpLo> SelfAdjointView<MatrixType, UpLo>::llt()
+inline LLT<typename SelfAdjointView<MatrixType, UpLo>::PlainObject, UpLo> SelfAdjointView<MatrixType, UpLo>::llt()
    const {
  return LLT<PlainObject, UpLo>(m_matrix);
 }
--- a/Eigen/src/Core/MatrixBase.h
+++ b/Eigen/src/Core/MatrixBase.h
@@ -338,14 +338,14 @@ class MatrixBase : public DenseBase<Derived> {
  /////////// LU module ///////////

  template <typename PermutationIndex = DefaultPermutationIndex>
-  inline const FullPivLU<PlainObject, PermutationIndex> fullPivLu() const;
+  inline FullPivLU<PlainObject, PermutationIndex> fullPivLu() const;
  template <typename PermutationIndex = DefaultPermutationIndex>
-  inline const PartialPivLU<PlainObject, PermutationIndex> partialPivLu() const;
+  inline PartialPivLU<PlainObject, PermutationIndex> partialPivLu() const;

  template <typename PermutationIndex = DefaultPermutationIndex>
-  inline const PartialPivLU<PlainObject, PermutationIndex> lu() const;
+  inline PartialPivLU<PlainObject, PermutationIndex> lu() const;

-  EIGEN_DEVICE_FUNC inline const Inverse<Derived> inverse() const;
+  EIGEN_DEVICE_FUNC inline Inverse<Derived> inverse() const;

  template <typename ResultType>
  inline void computeInverseAndDetWithCheck(
@@ -361,18 +361,18 @@ class MatrixBase : public DenseBase<Derived> {

  /////////// Cholesky module ///////////

-  inline const LLT<PlainObject> llt() const;
-  inline const LDLT<PlainObject> ldlt() const;
+  inline LLT<PlainObject> llt() const;
+  inline LDLT<PlainObject> ldlt() const;

  /////////// QR module ///////////

-  inline const HouseholderQR<PlainObject> householderQr() const;
+  inline HouseholderQR<PlainObject> householderQr() const;
  template <typename PermutationIndex = DefaultPermutationIndex>
-  inline const ColPivHouseholderQR<PlainObject, PermutationIndex> colPivHouseholderQr() const;
+  inline ColPivHouseholderQR<PlainObject, PermutationIndex> colPivHouseholderQr() const;
  template <typename PermutationIndex = DefaultPermutationIndex>
-  inline const FullPivHouseholderQR<PlainObject, PermutationIndex> fullPivHouseholderQr() const;
+  inline FullPivHouseholderQR<PlainObject, PermutationIndex> fullPivHouseholderQr() const;
  template <typename PermutationIndex = DefaultPermutationIndex>
-  inline const CompleteOrthogonalDecomposition<PlainObject, PermutationIndex> completeOrthogonalDecomposition() const;
+  inline CompleteOrthogonalDecomposition<PlainObject, PermutationIndex> completeOrthogonalDecomposition() const;

  /////////// Eigenvalues module ///////////

--- a/Eigen/src/Core/Random.h
+++ b/Eigen/src/Core/Random.h
@@ -19,7 +19,7 @@ namespace internal {

 template <typename Scalar>
 struct scalar_random_op {
-  inline const Scalar operator()() const { return random<Scalar>(); }
+  inline Scalar operator()() const { return random<Scalar>(); }
 };

 template <typename Scalar>
--- a/Eigen/src/Core/SelfAdjointView.h
+++ b/Eigen/src/Core/SelfAdjointView.h
@@ -219,8 +219,8 @@ class SelfAdjointView : public TriangularBase<SelfAdjointView<MatrixType_, UpLo>

  /////////// Cholesky module ///////////

-  const LLT<PlainObject, UpLo> llt() const;
-  const LDLT<PlainObject, UpLo> ldlt() const;
+  LLT<PlainObject, UpLo> llt() const;
+  LDLT<PlainObject, UpLo> ldlt() const;

  /////////// Eigenvalue module ///////////

--- a/Eigen/src/Core/SolverBase.h
+++ b/Eigen/src/Core/SolverBase.h
@@ -111,7 +111,7 @@ class SolverBase : public EigenBase<Derived> {
  /** \returns an expression of the solution x of \f$ A x = b \f$ using the current decomposition of A.
   */
  template <typename Rhs>
-  inline const Solve<Derived, Rhs> solve(const MatrixBase<Rhs>& b) const {
+  inline Solve<Derived, Rhs> solve(const MatrixBase<Rhs>& b) const {
    internal::solve_assertion<internal::remove_all_t<Derived>>::template run<false>(derived(), b);
    return Solve<Derived, Rhs>(derived(), b.derived());
  }
--- a/Eigen/src/Core/TriangularMatrix.h
+++ b/Eigen/src/Core/TriangularMatrix.h
@@ -244,7 +244,7 @@ class TriangularView
  }

  template <typename Other>
-  EIGEN_DEVICE_FUNC inline const Solve<TriangularView, Other> solve(const MatrixBase<Other>& other) const {
+  EIGEN_DEVICE_FUNC inline Solve<TriangularView, Other> solve(const MatrixBase<Other>& other) const {
    return Solve<TriangularView, Other>(*this, other.derived());
  }

--- a/Eigen/src/Core/functors/BinaryFunctors.h
+++ b/Eigen/src/Core/functors/BinaryFunctors.h
@@ -305,7 +305,7 @@ struct scalar_cmp_op<LhsScalar, RhsScalar, cmp_NEQ, UseTypedComparators> : binar
 */
 template <typename Scalar>
 struct scalar_hypot_op<Scalar, Scalar> : binary_op_base<Scalar, Scalar> {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& x, const Scalar& y) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& x, const Scalar& y) const {
    // This functor is used by hypotNorm only for which it is faster to first apply abs
    // on all coefficients prior to reduction through hypot.
    // This way we avoid calling abs on positive and real entries, and this also permits
@@ -342,7 +342,7 @@ struct scalar_pow_op : binary_op_base<Scalar, Exponent> {
  }

  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const {
    return generic_pow(a, b);
  }
 };
@@ -368,12 +368,12 @@ struct scalar_difference_op : binary_op_base<LhsScalar, RhsScalar> {
 #ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
  scalar_difference_op(){EIGEN_SCALAR_BINARY_OP_PLUGIN}
 #endif
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type
  operator()(const LhsScalar& a, const RhsScalar& b) const {
    return a - b;
  }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const {
    return internal::psub(a, b);
  }
 };
@@ -417,12 +417,12 @@ struct scalar_quotient_op : binary_op_base<LhsScalar, RhsScalar> {
 #ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
  scalar_quotient_op(){EIGEN_SCALAR_BINARY_OP_PLUGIN}
 #endif
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type
  operator()(const LhsScalar& a, const RhsScalar& b) const {
    return a / b;
  }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const {
    return internal::pdiv(a, b);
  }
 };
@@ -646,12 +646,12 @@ struct scalar_absolute_difference_op : binary_op_base<LhsScalar, RhsScalar> {
 #ifdef EIGEN_SCALAR_BINARY_OP_PLUGIN
  scalar_absolute_difference_op(){EIGEN_SCALAR_BINARY_OP_PLUGIN}
 #endif
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type
  operator()(const LhsScalar& a, const RhsScalar& b) const {
    return numext::absdiff(a, b);
  }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a, const Packet& b) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a, const Packet& b) const {
    return internal::pabsdiff(a, b);
  }
 };
@@ -704,12 +704,12 @@ struct bind1st_op : BinaryOp {

  EIGEN_DEVICE_FUNC explicit bind1st_op(const first_argument_type& val) : m_value(val) {}

-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator()(const second_argument_type& b) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator()(const second_argument_type& b) const {
    return BinaryOp::operator()(m_value, b);
  }

  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& b) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& b) const {
    return BinaryOp::packetOp(internal::pset1<Packet>(m_value), b);
  }

@@ -726,12 +726,12 @@ struct bind2nd_op : BinaryOp {

  EIGEN_DEVICE_FUNC explicit bind2nd_op(const second_argument_type& val) : m_value(val) {}

-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator()(const first_argument_type& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator()(const first_argument_type& a) const {
    return BinaryOp::operator()(a, m_value);
  }

  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return BinaryOp::packetOp(a, internal::pset1<Packet>(m_value));
  }

--- a/Eigen/src/Core/functors/NullaryFunctors.h
+++ b/Eigen/src/Core/functors/NullaryFunctors.h
@@ -20,9 +20,9 @@ namespace internal {
 template <typename Scalar>
 struct scalar_constant_op {
  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE scalar_constant_op(const Scalar& other) : m_other(other) {}
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()() const { return m_other; }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()() const { return m_other; }
  template <typename PacketType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const PacketType packetOp() const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE PacketType packetOp() const {
    return internal::pset1<PacketType>(m_other);
  }
  const Scalar m_other;
@@ -39,9 +39,9 @@ struct functor_traits<scalar_constant_op<Scalar>> {
 template <typename Scalar>
 struct scalar_zero_op {
  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE scalar_zero_op() = default;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()() const { return Scalar(0); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()() const { return Scalar(0); }
  template <typename PacketType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const PacketType packetOp() const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE PacketType packetOp() const {
    return internal::pzero<PacketType>(PacketType());
  }
 };
@@ -51,7 +51,7 @@ struct functor_traits<scalar_zero_op<Scalar>> : functor_traits<scalar_constant_o
 template <typename Scalar>
 struct scalar_identity_op {
  template <typename IndexType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(IndexType row, IndexType col) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(IndexType row, IndexType col) const {
    return row == col ? Scalar(1) : Scalar(0);
  }
 };
@@ -75,7 +75,7 @@ struct linspaced_op_impl<Scalar, /*IsInteger*/ false> {
        m_flip(numext::abs(high) < numext::abs(low)) {}

  template <typename IndexType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(IndexType i) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(IndexType i) const {
    if (m_flip)
      return (i == 0) ? m_low : Scalar(m_high - RealScalar(m_size1 - i) * m_step);
    else
@@ -83,7 +83,7 @@ struct linspaced_op_impl<Scalar, /*IsInteger*/ false> {
  }

  template <typename Packet, typename IndexType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(IndexType i) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(IndexType i) const {
    // Principle:
    // [low, ..., low] + ( [step, ..., step] * ( [i, ..., i] + [0, ..., size] ) )
    Packet low = pset1<Packet>(m_low);
@@ -119,7 +119,7 @@ struct linspaced_op_impl<Scalar, /*IsInteger*/ true> {
        m_use_divisor(num_steps > 1 && (numext::abs(high - low) + 1) < num_steps) {}

  template <typename IndexType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(IndexType i) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(IndexType i) const {
    if (m_use_divisor)
      return m_low + convert_index<Scalar>(i) / m_divisor;
    else
@@ -155,12 +155,12 @@ struct linspaced_op {
      : impl((num_steps == 1 ? high : low), high, num_steps) {}

  template <typename IndexType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(IndexType i) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(IndexType i) const {
    return impl(i);
  }

  template <typename Packet, typename IndexType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(IndexType i) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(IndexType i) const {
    return impl.template packetOp<Packet>(i);
  }

@@ -175,7 +175,7 @@ struct equalspaced_op {

  EIGEN_DEVICE_FUNC equalspaced_op(const Scalar& start, const Scalar& step) : m_start(start), m_step(step) {}
  template <typename IndexType>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(IndexType i) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(IndexType i) const {
    return m_start + m_step * static_cast<Scalar>(i);
  }
  template <typename Packet, typename IndexType>
--- a/Eigen/src/Core/functors/UnaryFunctors.h
+++ b/Eigen/src/Core/functors/UnaryFunctors.h
@@ -24,9 +24,9 @@ namespace internal {
 */
 template <typename Scalar>
 struct scalar_opposite_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const { return numext::negate(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return numext::negate(a); }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return internal::pnegate(a);
  }
 };
@@ -43,9 +43,9 @@ struct functor_traits<scalar_opposite_op<Scalar>> {
 template <typename Scalar>
 struct scalar_abs_op {
  typedef typename NumTraits<Scalar>::Real result_type;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator()(const Scalar& a) const { return numext::abs(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator()(const Scalar& a) const { return numext::abs(a); }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return internal::pabs(a);
  }
 };
@@ -71,7 +71,7 @@ template <typename Scalar, typename = void>
 struct abs_knowing_score {
  typedef typename NumTraits<Scalar>::Real result_type;
  template <typename Score>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator()(const Scalar& a, const Score&) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator()(const Scalar& a, const Score&) const {
    return numext::abs(a);
  }
 };
@@ -79,7 +79,7 @@ template <typename Scalar>
 struct abs_knowing_score<Scalar, typename scalar_score_coeff_op<Scalar>::Score_is_abs> {
  typedef typename NumTraits<Scalar>::Real result_type;
  template <typename Scal>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator()(const Scal&, const result_type& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator()(const Scal&, const result_type& a) const {
    return a;
  }
 };
@@ -92,9 +92,9 @@ struct abs_knowing_score<Scalar, typename scalar_score_coeff_op<Scalar>::Score_i
 template <typename Scalar>
 struct scalar_abs2_op {
  typedef typename NumTraits<Scalar>::Real result_type;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator()(const Scalar& a) const { return numext::abs2(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator()(const Scalar& a) const { return numext::abs2(a); }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return internal::pmul(a, a);
  }
 };
@@ -113,9 +113,9 @@ struct functor_traits<scalar_abs2_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_conjugate_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const { return numext::conj(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return numext::conj(a); }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return internal::pconj(a);
  }
 };
@@ -143,9 +143,9 @@ struct functor_traits<scalar_conjugate_op<Scalar>> {
 template <typename Scalar>
 struct scalar_arg_op {
  typedef typename NumTraits<Scalar>::Real result_type;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const result_type operator()(const Scalar& a) const { return numext::arg(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE result_type operator()(const Scalar& a) const { return numext::arg(a); }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return internal::parg(a);
  }
 };
@@ -165,11 +165,9 @@ struct functor_traits<scalar_arg_op<Scalar>> {
 template <typename Scalar>
 struct scalar_carg_op {
  using result_type = Scalar;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const {
-    return Scalar(numext::arg(a));
-  }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return Scalar(numext::arg(a)); }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return pcarg(a);
  }
 };
@@ -187,9 +185,7 @@ struct functor_traits<scalar_carg_op<Scalar>> {
 template <typename Scalar, typename NewType>
 struct scalar_cast_op {
  typedef NewType result_type;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const NewType operator()(const Scalar& a) const {
-    return cast<Scalar, NewType>(a);
-  }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE NewType operator()(const Scalar& a) const { return cast<Scalar, NewType>(a); }
 };

 template <typename Scalar, typename NewType>
@@ -222,11 +218,11 @@ struct functor_traits<core_cast_op<SrcType, DstType>> {
 */
 template <typename Scalar, int N>
 struct scalar_shift_right_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const {
    return numext::arithmetic_shift_right(a);
  }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return internal::parithmetic_shift_right<N>(a);
  }
 };
@@ -242,11 +238,11 @@ struct functor_traits<scalar_shift_right_op<Scalar, N>> {
 */
 template <typename Scalar, int N>
 struct scalar_shift_left_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const {
    return numext::logical_shift_left(a);
  }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet packetOp(const Packet& a) const {
    return internal::plogical_shift_left<N>(a);
  }
 };
@@ -329,7 +325,7 @@ struct functor_traits<scalar_imag_ref_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_exp_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return internal::pexp(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return internal::pexp(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pexp(a);
@@ -361,7 +357,7 @@ struct functor_traits<scalar_exp_op<Scalar>> {

 template <typename Scalar>
 struct scalar_exp2_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return internal::pexp2(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return internal::pexp2(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pexp2(a);
@@ -383,7 +379,7 @@ struct functor_traits<scalar_exp2_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_expm1_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::expm1(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::expm1(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pexpm1(a);
@@ -405,7 +401,7 @@ struct functor_traits<scalar_expm1_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_log_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::log(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::log(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::plog(a);
@@ -437,7 +433,7 @@ struct functor_traits<scalar_log_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_log1p_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::log1p(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::log1p(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::plog1p(a);
@@ -459,7 +455,7 @@ struct functor_traits<scalar_log1p_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_log10_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { EIGEN_USING_STD(log10) return log10(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { EIGEN_USING_STD(log10) return log10(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::plog10(a);
@@ -479,7 +475,7 @@ struct functor_traits<scalar_log10_op<Scalar>> {
 template <typename Scalar>
 struct scalar_log2_op {
  using RealScalar = typename NumTraits<Scalar>::Real;
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const {
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const {
    return Scalar(RealScalar(EIGEN_LOG2E)) * numext::log(a);
  }
  template <typename Packet>
@@ -498,7 +494,7 @@ struct functor_traits<scalar_log2_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_sqrt_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::sqrt(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::sqrt(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::psqrt(a);
@@ -540,7 +536,7 @@ struct functor_traits<scalar_sqrt_op<bool>> {
 */
 template <typename Scalar>
 struct scalar_cbrt_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::cbrt(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::cbrt(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pcbrt(a);
@@ -558,7 +554,7 @@ struct functor_traits<scalar_cbrt_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_rsqrt_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::rsqrt(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::rsqrt(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::prsqrt(a);
@@ -593,7 +589,7 @@ struct functor_traits<scalar_cos_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_sin_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::sin(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::sin(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::psin(a);
@@ -610,7 +606,7 @@ struct functor_traits<scalar_sin_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_tan_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::tan(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::tan(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::ptan(a);
@@ -627,7 +623,7 @@ struct functor_traits<scalar_tan_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_acos_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::acos(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::acos(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pacos(a);
@@ -644,7 +640,7 @@ struct functor_traits<scalar_acos_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_asin_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::asin(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::asin(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pasin(a);
@@ -661,7 +657,7 @@ struct functor_traits<scalar_asin_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_atan_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::atan(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::atan(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::patan(a);
@@ -678,7 +674,7 @@ struct functor_traits<scalar_atan_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_tanh_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::tanh(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::tanh(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& x) const {
    return ptanh(x);
@@ -713,7 +709,7 @@ struct functor_traits<scalar_tanh_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_atanh_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::atanh(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::atanh(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& x) const {
    return patanh(x);
@@ -731,7 +727,7 @@ struct functor_traits<scalar_atanh_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_sinh_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::sinh(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::sinh(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::psinh(a);
@@ -748,7 +744,7 @@ struct functor_traits<scalar_sinh_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_asinh_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::asinh(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::asinh(a); }
 };

 template <typename Scalar>
@@ -762,7 +758,7 @@ struct functor_traits<scalar_asinh_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_cosh_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::cosh(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::cosh(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pcosh(a);
@@ -779,7 +775,7 @@ struct functor_traits<scalar_cosh_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_acosh_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::acosh(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::acosh(a); }
 };

 template <typename Scalar>
@@ -795,7 +791,7 @@ template <typename Scalar>
 struct scalar_inverse_op {
  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return Scalar(1) / a; }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::preciprocal(a);
  }
 };
@@ -819,7 +815,7 @@ template <typename Scalar>
 struct scalar_square_op {
  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return a * a; }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pmul(a, a);
  }
 };
@@ -833,7 +829,7 @@ template <>
 struct scalar_square_op<bool> {
  EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline bool operator()(const bool& a) const { return a; }
  template <typename Packet>
-  EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const {
+  EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return a;
  }
 };
@@ -850,7 +846,7 @@ template <typename Scalar>
 struct scalar_cube_op {
  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return a * a * a; }
  template <typename Packet>
-  EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const {
+  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pmul(a, pmul(a, a));
  }
 };
@@ -864,7 +860,7 @@ template <>
 struct scalar_cube_op<bool> {
  EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline bool operator()(const bool& a) const { return a; }
  template <typename Packet>
-  EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline const Packet packetOp(const Packet& a) const {
+  EIGEN_DEPRECATED EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return a;
  }
 };
@@ -879,7 +875,7 @@ struct functor_traits<scalar_cube_op<bool>> {
 */
 template <typename Scalar>
 struct scalar_round_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const { return numext::round(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return numext::round(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pround(a);
@@ -899,7 +895,7 @@ struct functor_traits<scalar_round_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_floor_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const { return numext::floor(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return numext::floor(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pfloor(a);
@@ -919,7 +915,7 @@ struct functor_traits<scalar_floor_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_rint_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const { return numext::rint(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return numext::rint(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::print(a);
@@ -939,7 +935,7 @@ struct functor_traits<scalar_rint_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_ceil_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const { return numext::ceil(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return numext::ceil(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::pceil(a);
@@ -959,7 +955,7 @@ struct functor_traits<scalar_ceil_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_trunc_op {
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Scalar operator()(const Scalar& a) const { return numext::trunc(a); }
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Scalar operator()(const Scalar& a) const { return numext::trunc(a); }
  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
    return internal::ptrunc(a);
@@ -1153,7 +1149,7 @@ struct functor_traits<scalar_bitwise_not_op<Scalar>> {
 */
 template <typename Scalar>
 struct scalar_sign_op {
-  EIGEN_DEVICE_FUNC inline const Scalar operator()(const Scalar& a) const { return numext::sign(a); }
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a) const { return numext::sign(a); }

  template <typename Packet>
  EIGEN_DEVICE_FUNC inline Packet packetOp(const Packet& a) const {
--- a/Eigen/src/IterativeLinearSolvers/BasicPreconditioners.h
+++ b/Eigen/src/IterativeLinearSolvers/BasicPreconditioners.h
@@ -86,7 +86,7 @@ class DiagonalPreconditioner {
  }

  template <typename Rhs>
-  inline const Solve<DiagonalPreconditioner, Rhs> solve(const MatrixBase<Rhs>& b) const {
+  inline Solve<DiagonalPreconditioner, Rhs> solve(const MatrixBase<Rhs>& b) const {
    eigen_assert(m_isInitialized && "DiagonalPreconditioner is not initialized.");
    eigen_assert(m_invdiag.size() == b.rows() &&
                 "DiagonalPreconditioner::solve(): invalid number of rows of the right hand side matrix b");
--- a/Eigen/src/LU/FullPivLU.h
+++ b/Eigen/src/LU/FullPivLU.h
@@ -247,7 +247,7 @@ class FullPivLU : public SolverBase<FullPivLU<MatrixType_, PermutationIndex_> >
   * \sa TriangularView::solve(), kernel(), inverse()
   */
  template <typename Rhs>
-  inline const Solve<FullPivLU, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<FullPivLU, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  /** \returns an estimate of the reciprocal condition number of the matrix of which \c *this is
@@ -394,7 +394,7 @@ class FullPivLU : public SolverBase<FullPivLU<MatrixType_, PermutationIndex_> >
   *
   * \sa MatrixBase::inverse()
   */
-  inline const Inverse<FullPivLU> inverse() const {
+  inline Inverse<FullPivLU> inverse() const {
    eigen_assert(m_isInitialized && "LU is not initialized.");
    eigen_assert(m_lu.rows() == m_lu.cols() && "You can't take the inverse of a non-square matrix!");
    return Inverse<FullPivLU>(*this);
@@ -816,8 +816,7 @@ struct Assignment<
 */
 template <typename Derived>
 template <typename PermutationIndex>
-inline const FullPivLU<typename MatrixBase<Derived>::PlainObject, PermutationIndex> MatrixBase<Derived>::fullPivLu()
-    const {
+inline FullPivLU<typename MatrixBase<Derived>::PlainObject, PermutationIndex> MatrixBase<Derived>::fullPivLu() const {
  return FullPivLU<PlainObject, PermutationIndex>(eval());
 }

--- a/Eigen/src/LU/InverseImpl.h
+++ b/Eigen/src/LU/InverseImpl.h
@@ -276,7 +276,7 @@ struct Assignment<DstXprType, Inverse<XprType>,
 * \sa computeInverseAndDetWithCheck()
 */
 template <typename Derived>
-EIGEN_DEVICE_FUNC inline const Inverse<Derived> MatrixBase<Derived>::inverse() const {
+EIGEN_DEVICE_FUNC inline Inverse<Derived> MatrixBase<Derived>::inverse() const {
  EIGEN_STATIC_ASSERT(!NumTraits<Scalar>::IsInteger, THIS_FUNCTION_IS_NOT_FOR_INTEGER_NUMERIC_TYPES)
  eigen_assert(rows() == cols());
  return Inverse<Derived>(derived());
--- a/Eigen/src/LU/PartialPivLU.h
+++ b/Eigen/src/LU/PartialPivLU.h
@@ -181,7 +181,7 @@ class PartialPivLU : public SolverBase<PartialPivLU<MatrixType_, PermutationInde
   * \sa TriangularView::solve(), inverse(), computeInverse()
   */
  template <typename Rhs>
-  inline const Solve<PartialPivLU, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<PartialPivLU, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  /** \returns an estimate of the reciprocal condition number of the matrix of which \c *this is
@@ -199,7 +199,7 @@ class PartialPivLU : public SolverBase<PartialPivLU<MatrixType_, PermutationInde
   *
   * \sa MatrixBase::inverse(), LU::inverse()
   */
-  inline const Inverse<PartialPivLU> inverse() const {
+  inline Inverse<PartialPivLU> inverse() const {
    eigen_assert(m_isInitialized && "PartialPivLU is not initialized.");
    return Inverse<PartialPivLU>(*this);
  }
@@ -562,8 +562,8 @@ struct Assignment<
 */
 template <typename Derived>
 template <typename PermutationIndex>
-inline const PartialPivLU<typename MatrixBase<Derived>::PlainObject, PermutationIndex>
-MatrixBase<Derived>::partialPivLu() const {
+inline PartialPivLU<typename MatrixBase<Derived>::PlainObject, PermutationIndex> MatrixBase<Derived>::partialPivLu()
+    const {
  return PartialPivLU<PlainObject, PermutationIndex>(eval());
 }

@@ -577,7 +577,7 @@ MatrixBase<Derived>::partialPivLu() const {
 */
 template <typename Derived>
 template <typename PermutationIndex>
-inline const PartialPivLU<typename MatrixBase<Derived>::PlainObject, PermutationIndex> MatrixBase<Derived>::lu() const {
+inline PartialPivLU<typename MatrixBase<Derived>::PlainObject, PermutationIndex> MatrixBase<Derived>::lu() const {
  return PartialPivLU<PlainObject, PermutationIndex>(eval());
 }

--- a/Eigen/src/QR/ColPivHouseholderQR.h
+++ b/Eigen/src/QR/ColPivHouseholderQR.h
@@ -158,7 +158,7 @@ class ColPivHouseholderQR : public SolverBase<ColPivHouseholderQR<MatrixType_, P
   * Output: \verbinclude ColPivHouseholderQR_solve.out
   */
  template <typename Rhs>
-  inline const Solve<ColPivHouseholderQR, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<ColPivHouseholderQR, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  HouseholderSequenceType householderQ() const;
@@ -318,7 +318,7 @@ class ColPivHouseholderQR : public SolverBase<ColPivHouseholderQR<MatrixType_, P
   * \note If this matrix is not invertible, the returned matrix has undefined coefficients.
   *       Use isInvertible() to first determine whether this matrix is invertible.
   */
-  inline const Inverse<ColPivHouseholderQR> inverse() const {
+  inline Inverse<ColPivHouseholderQR> inverse() const {
    eigen_assert(m_isInitialized && "ColPivHouseholderQR is not initialized.");
    return Inverse<ColPivHouseholderQR>(*this);
  }
@@ -664,7 +664,7 @@ ColPivHouseholderQR<MatrixType, PermutationIndex>::householderQ() const {
 */
 template <typename Derived>
 template <typename PermutationIndexType>
-const ColPivHouseholderQR<typename MatrixBase<Derived>::PlainObject, PermutationIndexType>
+ColPivHouseholderQR<typename MatrixBase<Derived>::PlainObject, PermutationIndexType>
 MatrixBase<Derived>::colPivHouseholderQr() const {
  return ColPivHouseholderQR<PlainObject, PermutationIndexType>(eval());
 }
--- a/Eigen/src/QR/CompleteOrthogonalDecomposition.h
+++ b/Eigen/src/QR/CompleteOrthogonalDecomposition.h
@@ -140,7 +140,7 @@ class CompleteOrthogonalDecomposition
   *
   */
  template <typename Rhs>
-  inline const Solve<CompleteOrthogonalDecomposition, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<CompleteOrthogonalDecomposition, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  HouseholderSequenceType householderQ(void) const;
@@ -293,7 +293,7 @@ class CompleteOrthogonalDecomposition
   * \warning: Do not compute \c this->pseudoInverse()*rhs to solve a linear systems.
   * It is more efficient and numerically stable to call \c this->solve(rhs).
   */
-  inline const Inverse<CompleteOrthogonalDecomposition> pseudoInverse() const {
+  inline Inverse<CompleteOrthogonalDecomposition> pseudoInverse() const {
    eigen_assert(m_cpqr.m_isInitialized && "CompleteOrthogonalDecomposition is not initialized.");
    return Inverse<CompleteOrthogonalDecomposition>(*this);
  }
@@ -638,7 +638,7 @@ CompleteOrthogonalDecomposition<MatrixType, PermutationIndex>::householderQ() co
 */
 template <typename Derived>
 template <typename PermutationIndex>
-const CompleteOrthogonalDecomposition<typename MatrixBase<Derived>::PlainObject, PermutationIndex>
+CompleteOrthogonalDecomposition<typename MatrixBase<Derived>::PlainObject, PermutationIndex>
 MatrixBase<Derived>::completeOrthogonalDecomposition() const {
  return CompleteOrthogonalDecomposition<PlainObject>(eval());
 }
--- a/Eigen/src/QR/FullPivHouseholderQR.h
+++ b/Eigen/src/QR/FullPivHouseholderQR.h
@@ -186,7 +186,7 @@ class FullPivHouseholderQR : public SolverBase<FullPivHouseholderQR<MatrixType_,
   * Output: \verbinclude FullPivHouseholderQR_solve.out
   */
  template <typename Rhs>
-  inline const Solve<FullPivHouseholderQR, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<FullPivHouseholderQR, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  /** \returns Expression object representing the matrix Q
@@ -339,7 +339,7 @@ class FullPivHouseholderQR : public SolverBase<FullPivHouseholderQR<MatrixType_,
   * \note If this matrix is not invertible, the returned matrix has undefined coefficients.
   *       Use isInvertible() to first determine whether this matrix is invertible.
   */
-  inline const Inverse<FullPivHouseholderQR> inverse() const {
+  inline Inverse<FullPivHouseholderQR> inverse() const {
    eigen_assert(m_isInitialized && "FullPivHouseholderQR is not initialized.");
    return Inverse<FullPivHouseholderQR>(*this);
  }
@@ -723,7 +723,7 @@ FullPivHouseholderQR<MatrixType, PermutationIndex>::matrixQ() const {
 */
 template <typename Derived>
 template <typename PermutationIndex>
-const FullPivHouseholderQR<typename MatrixBase<Derived>::PlainObject, PermutationIndex>
+FullPivHouseholderQR<typename MatrixBase<Derived>::PlainObject, PermutationIndex>
 MatrixBase<Derived>::fullPivHouseholderQr() const {
  return FullPivHouseholderQR<PlainObject, PermutationIndex>(eval());
 }
--- a/Eigen/src/QR/HouseholderQR.h
+++ b/Eigen/src/QR/HouseholderQR.h
@@ -156,7 +156,7 @@ class HouseholderQR : public SolverBase<HouseholderQR<MatrixType_>> {
   * Output: \verbinclude HouseholderQR_solve.out
   */
  template <typename Rhs>
-  inline const Solve<HouseholderQR, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<HouseholderQR, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  /** This method returns an expression of the unitary matrix Q as a sequence of Householder transformations.
@@ -534,7 +534,7 @@ void HouseholderQR<MatrixType>::computeInPlace() {
 * \sa class HouseholderQR
 */
 template <typename Derived>
-const HouseholderQR<typename MatrixBase<Derived>::PlainObject> MatrixBase<Derived>::householderQr() const {
+HouseholderQR<typename MatrixBase<Derived>::PlainObject> MatrixBase<Derived>::householderQr() const {
  return HouseholderQR<PlainObject>(eval());
 }

--- a/Eigen/src/SVD/SVDBase.h
+++ b/Eigen/src/SVD/SVDBase.h
@@ -290,7 +290,7 @@ class SVDBase : public SolverBase<SVDBase<Derived> > {
   * A x - b \Vert \f$.
   */
  template <typename Rhs>
-  inline const Solve<Derived, Rhs> solve(const MatrixBase<Rhs>& b) const;
+  inline Solve<Derived, Rhs> solve(const MatrixBase<Rhs>& b) const;
 #endif

  /** \brief Reports whether previous computation was successful.
--- a/Eigen/src/SparseCore/SparseSolverBase.h
+++ b/Eigen/src/SparseCore/SparseSolverBase.h
@@ -81,7 +81,7 @@ class SparseSolverBase : internal::noncopyable {
   * \sa compute()
   */
  template <typename Rhs>
-  inline const Solve<Derived, Rhs> solve(const MatrixBase<Rhs>& b) const {
+  inline Solve<Derived, Rhs> solve(const MatrixBase<Rhs>& b) const {
    eigen_assert(m_isInitialized && "Solver is not initialized.");
    eigen_assert(derived().rows() == b.rows() && "solve(): invalid number of rows of the right hand side matrix b");
    return Solve<Derived, Rhs>(derived(), b.derived());
@@ -92,7 +92,7 @@ class SparseSolverBase : internal::noncopyable {
   * \sa compute()
   */
  template <typename Rhs>
-  inline const Solve<Derived, Rhs> solve(const SparseMatrixBase<Rhs>& b) const {
+  inline Solve<Derived, Rhs> solve(const SparseMatrixBase<Rhs>& b) const {
    eigen_assert(m_isInitialized && "Solver is not initialized.");
    eigen_assert(derived().rows() == b.rows() && "solve(): invalid number of rows of the right hand side matrix b");
    return Solve<Derived, Rhs>(derived(), b.derived());
--- a/Eigen/src/SparseLU/SparseLU.h
+++ b/Eigen/src/SparseLU/SparseLU.h
@@ -310,7 +310,7 @@ class SparseLU : public SparseSolverBase<SparseLU<MatrixType_, OrderingType_>>,
   * \sa compute()
   */
  template <typename Rhs>
-  inline const Solve<SparseLU, Rhs> solve(const MatrixBase<Rhs>& B) const;
+  inline Solve<SparseLU, Rhs> solve(const MatrixBase<Rhs>& B) const;
 #endif  // EIGEN_PARSED_BY_DOXYGEN

  /** \brief Reports whether previous computation was successful.
--- a/Eigen/src/SparseQR/SparseQR.h
+++ b/Eigen/src/SparseQR/SparseQR.h
@@ -241,14 +241,14 @@ class SparseQR : public SparseSolverBase<SparseQR<MatrixType_, OrderingType_> >
   * \sa compute()
   */
  template <typename Rhs>
-  inline const Solve<SparseQR, Rhs> solve(const MatrixBase<Rhs>& B) const {
+  inline Solve<SparseQR, Rhs> solve(const MatrixBase<Rhs>& B) const {
    eigen_assert(m_isInitialized && "The factorization should be called first, use compute()");
    eigen_assert(this->rows() == B.rows() &&
                 "SparseQR::solve() : invalid number of rows in the right hand side matrix");
    return Solve<SparseQR, Rhs>(*this, B.derived());
  }
  template <typename Rhs>
-  inline const Solve<SparseQR, Rhs> solve(const SparseMatrixBase<Rhs>& B) const {
+  inline Solve<SparseQR, Rhs> solve(const SparseMatrixBase<Rhs>& B) const {
    eigen_assert(m_isInitialized && "The factorization should be called first, use compute()");
    eigen_assert(this->rows() == B.rows() &&
                 "SparseQR::solve() : invalid number of rows in the right hand side matrix");