// SPDX-License-Identifier: Apache-2.0
// 
// Copyright 2008-2016 Conrad Sanderson (https://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// https://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------


//! \addtogroup unwrap
//! @{


// TODO: document the conditions and restrictions for the use of each unwrap variant:
// TODO: unwrap, unwrap_check, quasi_unwrap, partial_unwrap


template<typename T1>
struct unwrap_default
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  unwrap_default(const T1& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT> M;
  };



template<typename T1>
struct unwrap_fixed
  {
  typedef T1 stored_type;
  
  inline explicit
  unwrap_fixed(const T1& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const T1& M;
  };



template<typename T1, bool condition>
struct unwrap_redirect {};

template<typename T1>
struct unwrap_redirect<T1, false> { typedef unwrap_default<T1> result; };

template<typename T1>
struct unwrap_redirect<T1, true>  { typedef unwrap_fixed<T1>   result; };


template<typename T1>
struct unwrap : public unwrap_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  inline
  unwrap(const T1& A)
    : unwrap_redirect<T1, is_Mat_fixed<T1>::value>::result(A)
    {
    }
  };



template<typename eT>
struct unwrap< Mat<eT> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  unwrap(const Mat<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT>& M;
  };



template<typename eT>
struct unwrap< Row<eT> >
  {
  typedef Row<eT> stored_type;
  
  inline
  unwrap(const Row<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Row<eT>& M;
  };



template<typename eT>
struct unwrap< Col<eT> >
  {
  typedef Col<eT> stored_type;

  inline
  unwrap(const Col<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Col<eT>& M;
  };



template<typename eT>
struct unwrap< subview_col<eT> >
  {
  typedef Col<eT> stored_type;

  inline
  unwrap(const subview_col<eT>& A)
    : M(A.colmem, A.n_rows)
    {
    arma_debug_sigprint();
    }
  
  const Col<eT> M;
  };



template<typename eT>
struct unwrap< subview_cols<eT> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  unwrap(const subview_cols<eT>& A)
    : M(A.colptr(0), A.n_rows, A.n_cols)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT> M;
  };



template<typename out_eT, typename T1, typename T2, typename glue_type>
struct unwrap< mtGlue<out_eT, T1, T2, glue_type> >
  {
  typedef Mat<out_eT> stored_type;
  
  inline
  unwrap(const mtGlue<out_eT, T1, T2, glue_type>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<out_eT> M;
  };



template<typename out_eT, typename T1, typename op_type>
struct unwrap< mtOp<out_eT, T1, op_type> >
  {
  typedef Mat<out_eT> stored_type;
  
  inline
  unwrap(const mtOp<out_eT, T1, op_type>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<out_eT> M;
  };



//
//
//



template<typename T1>
struct quasi_unwrap_default
  {
  typedef typename T1::elem_type eT;
  
  inline
  quasi_unwrap_default(const T1& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  // NOTE: DO NOT DIRECTLY CHECK FOR ALIASING BY TAKING THE ADDRESS OF THE "M" OBJECT IN ANY quasi_unwrap CLASS !!!
  Mat<eT> M;
  
  static constexpr bool is_const     = false;
  static constexpr bool has_subview  = false;
  static constexpr bool has_orig_mem = false;
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  };



template<typename T1>
struct quasi_unwrap_fixed
  {
  typedef typename T1::elem_type eT;
  
  inline explicit
  quasi_unwrap_fixed(const T1& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const T1& M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = false;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&M) == void_ptr(&X)); }
  };



template<typename T1, bool condition>
struct quasi_unwrap_redirect {};

template<typename T1>
struct quasi_unwrap_redirect<T1, false> { typedef quasi_unwrap_default<T1> result; };

template<typename T1>
struct quasi_unwrap_redirect<T1, true>  { typedef quasi_unwrap_fixed<T1>   result; };


template<typename T1>
struct quasi_unwrap : public quasi_unwrap_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  typedef typename quasi_unwrap_redirect<T1, is_Mat_fixed<T1>::value>::result quasi_unwrap_extra;
  
  inline
  quasi_unwrap(const T1& A)
    : quasi_unwrap_extra(A)
    {
    }
  
  static constexpr bool is_const     = quasi_unwrap_extra::is_const;
  static constexpr bool has_subview  = quasi_unwrap_extra::has_subview;
  static constexpr bool has_orig_mem = quasi_unwrap_extra::has_orig_mem;
  
  using quasi_unwrap_extra::M;
  using quasi_unwrap_extra::is_alias;
  };



template<typename eT>
struct quasi_unwrap< Mat<eT> >
  {
  inline
  quasi_unwrap(const Mat<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT>& M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = false;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&M) == void_ptr(&X)); }
  };



template<typename eT>
struct quasi_unwrap< Row<eT> >
  {
  
  inline
  quasi_unwrap(const Row<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Row<eT>& M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = false;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&M) == void_ptr(&X)); }
  };



template<typename eT>
struct quasi_unwrap< Col<eT> >
  {
  inline
  quasi_unwrap(const Col<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Col<eT>& M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = false;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&M) == void_ptr(&X)); }
  };



template<typename eT>
struct quasi_unwrap< subview<eT> >
  {
  inline
  quasi_unwrap(const subview<eT>& A)
    : sv( A                                                  )
    , M ( A, ((A.aux_row1 == 0) && (A.n_rows == A.m.n_rows)) )  // reuse memory if the subview is a contiguous chunk
    {
    arma_debug_sigprint();
    }
  
  const subview<eT>& sv;
  const Mat<eT>      M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = false;  // NOTE: set to false as this is the general case; original memory is only used when the subview is a contiguous chunk
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && ( ((sv.aux_row1 == 0) && (sv.n_rows == sv.m.n_rows)) ? (void_ptr(&(sv.m)) == void_ptr(&X)) : false ); }
  };



template<typename eT>
struct quasi_unwrap< subview_row<eT> >
  {
  inline
  quasi_unwrap(const subview_row<eT>& A)
    : sv( A                    )
    , M ( A, (A.m.n_rows == 1) )
    {
    arma_debug_sigprint();
    }
  
  const subview_row<eT>& sv;
  const Row<eT>          M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = false;  // NOTE: set to false as this is the general case; original memory is only used when the subview is a contiguous chunk
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && ( (sv.m.n_rows == 1) ? (void_ptr(&X) == void_ptr(&(sv.m))) : false ); }
  };



template<typename eT>
struct quasi_unwrap< subview_col<eT> >
  {
  inline
  quasi_unwrap(const subview_col<eT>& A)
    : orig( A.m )
    , M  ( const_cast<eT*>( A.colmem ), A.n_rows, false, false )
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT>& orig;
  const Col<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&orig) == void_ptr(&X)); }
  };



template<typename eT>
struct quasi_unwrap< subview_cols<eT> >
  {
  inline
  quasi_unwrap(const subview_cols<eT>& A)
    : orig( A.m )
    , M   ( const_cast<eT*>( A.colptr(0) ), A.n_rows, A.n_cols, false, false )
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT>& orig;
  const Mat<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&orig) == void_ptr(&X)); }
  };



template<typename out_eT, typename T1, typename T2, typename glue_type>
struct quasi_unwrap< mtGlue<out_eT, T1, T2, glue_type> >
  {
  inline
  quasi_unwrap(const mtGlue<out_eT, T1, T2, glue_type>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  Mat<out_eT> M;
  
  static constexpr bool is_const     = false;
  static constexpr bool has_subview  = false;
  static constexpr bool has_orig_mem = false;
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  };



template<typename out_eT, typename T1, typename op_type>
struct quasi_unwrap< mtOp<out_eT, T1, op_type> >
  {
  inline
  quasi_unwrap(const mtOp<out_eT, T1, op_type>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  Mat<out_eT> M;
  
  static constexpr bool is_const     = false;
  static constexpr bool has_subview  = false;
  static constexpr bool has_orig_mem = false;
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  };



template<typename T1>
struct quasi_unwrap< Op<T1, op_vectorise_col> >
  {
  typedef typename T1::elem_type eT;
  
  inline
  quasi_unwrap(const Op<T1, op_vectorise_col>& A)
    : U( A.m )
    , M( const_cast<eT*>(U.M.memptr()), U.M.n_elem, 1, false, false )
    {
    arma_debug_sigprint();
    }
  
  const quasi_unwrap<T1> U;
  const Mat<eT>          M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && U.is_alias(X); }
  };



template<typename eT>
struct quasi_unwrap< Op<Col<eT>, op_strans> >
  {
  inline
  quasi_unwrap(const Op<Col<eT>, op_strans>& A)
    : orig(A.m)
    , M   (const_cast<eT*>(A.m.memptr()), A.m.n_elem, false, false)
    {
    arma_debug_sigprint();
    }
  
  const Col<eT>& orig;
  const Row<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&orig) == void_ptr(&X)); }
  };



template<typename eT>
struct quasi_unwrap< Op<Row<eT>, op_strans> >
  {
  inline
  quasi_unwrap(const Op<Row<eT>, op_strans>& A)
    : orig(A.m)
    , M   (const_cast<eT*>(A.m.memptr()), A.m.n_elem, false, false)
    {
    arma_debug_sigprint();
    }
  
  const Row<eT>& orig;
  const Col<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&orig) == void_ptr(&X)); }
  };



template<typename eT>
struct quasi_unwrap< Op<subview_col<eT>, op_strans> >
  {
  inline
  quasi_unwrap(const Op<subview_col<eT>, op_strans>& A)
    : orig( A.m.m )
    , M   ( const_cast<eT*>( A.m.colmem ), A.m.n_rows, false, false )
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT>& orig;
  const Row<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&X) == void_ptr(&orig)); }
  };



template<typename T1>
struct quasi_unwrap_Col_htrans
  {
  inline quasi_unwrap_Col_htrans(const T1&) {}
  };



template<typename eT>
struct quasi_unwrap_Col_htrans< Op<Col<eT>, op_htrans> >
  {
  inline
  quasi_unwrap_Col_htrans(const Op<Col<eT>, op_htrans>& A)
    : orig(A.m)
    , M   (const_cast<eT*>(A.m.memptr()), A.m.n_elem, false, false)
    {
    arma_debug_sigprint();
    }
  
  const Col<eT>& orig;
  const Row<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&orig) == void_ptr(&X)); }
  };



template<typename T1, bool condition>
struct quasi_unwrap_Col_htrans_redirect {};

template<typename T1>
struct quasi_unwrap_Col_htrans_redirect<T1, true>  { typedef quasi_unwrap_default<T1>    result; };

template<typename T1>
struct quasi_unwrap_Col_htrans_redirect<T1, false> { typedef quasi_unwrap_Col_htrans<T1> result; };


template<typename eT>
struct quasi_unwrap< Op<Col<eT>, op_htrans> >
  : public quasi_unwrap_Col_htrans_redirect< Op<Col<eT>, op_htrans>, is_cx<eT>::value >::result
  {
  typedef typename quasi_unwrap_Col_htrans_redirect< Op<Col<eT>, op_htrans>, is_cx<eT>::value >::result quasi_unwrap_Col_htrans_extra;
  
  inline
  quasi_unwrap(const Op<Col<eT>, op_htrans>& A)
    : quasi_unwrap_Col_htrans_extra(A)
    {
    }
  
  static constexpr bool is_const     = quasi_unwrap_Col_htrans_extra::is_const;
  static constexpr bool has_subview  = quasi_unwrap_Col_htrans_extra::has_subview;
  static constexpr bool has_orig_mem = quasi_unwrap_Col_htrans_extra::has_orig_mem;
  
  using quasi_unwrap_Col_htrans_extra::M;
  using quasi_unwrap_Col_htrans_extra::is_alias;
  };



template<typename T1>
struct quasi_unwrap_Row_htrans
  {
  inline quasi_unwrap_Row_htrans(const T1&) {}
  };



template<typename eT>
struct quasi_unwrap_Row_htrans< Op<Row<eT>, op_htrans> >
  {
  inline
  quasi_unwrap_Row_htrans(const Op<Row<eT>, op_htrans>& A)
    : orig(A.m)
    , M   (const_cast<eT*>(A.m.memptr()), A.m.n_elem, false, false)
    {
    arma_debug_sigprint();
    }
  
  const Row<eT>& orig;
  const Col<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&orig) == void_ptr(&X)); }
  };



template<typename T1, bool condition>
struct quasi_unwrap_Row_htrans_redirect {};

template<typename T1>
struct quasi_unwrap_Row_htrans_redirect<T1, true>  { typedef quasi_unwrap_default<T1>    result; };

template<typename T1>
struct quasi_unwrap_Row_htrans_redirect<T1, false> { typedef quasi_unwrap_Row_htrans<T1> result; };


template<typename eT>
struct quasi_unwrap< Op<Row<eT>, op_htrans> >
  : public quasi_unwrap_Row_htrans_redirect< Op<Row<eT>, op_htrans>, is_cx<eT>::value >::result
  {
  typedef typename quasi_unwrap_Row_htrans_redirect< Op<Row<eT>, op_htrans>, is_cx<eT>::value >::result quasi_unwrap_Row_htrans_extra;
  
  inline
  quasi_unwrap(const Op<Row<eT>, op_htrans>& A)
    : quasi_unwrap_Row_htrans_extra(A)
    {
    }
  
  static constexpr bool is_const     = quasi_unwrap_Row_htrans_extra::is_const;
  static constexpr bool has_subview  = quasi_unwrap_Row_htrans_extra::has_subview;
  static constexpr bool has_orig_mem = quasi_unwrap_Row_htrans_extra::has_orig_mem;
  
  using quasi_unwrap_Row_htrans_extra::M;
  using quasi_unwrap_Row_htrans_extra::is_alias;
  };



template<typename T1>
struct quasi_unwrap_subview_col_htrans
  {
  inline quasi_unwrap_subview_col_htrans(const T1&) {}
  };



template<typename eT>
struct quasi_unwrap_subview_col_htrans< Op<subview_col<eT>, op_htrans> >
  {
  inline
  quasi_unwrap_subview_col_htrans(const Op<subview_col<eT>, op_htrans>& A)
    : orig(A.m.m)
    , M   (const_cast<eT*>(A.m.colmem), A.m.n_rows, false, false)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT>& orig;
  const Row<eT>  M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&orig) == void_ptr(&X)); }
  };



template<typename T1, bool condition>
struct quasi_unwrap_subview_col_htrans_redirect {};

template<typename T1>
struct quasi_unwrap_subview_col_htrans_redirect<T1, true>  { typedef quasi_unwrap_default<T1>            result; };

template<typename T1>
struct quasi_unwrap_subview_col_htrans_redirect<T1, false> { typedef quasi_unwrap_subview_col_htrans<T1> result; };


template<typename eT>
struct quasi_unwrap< Op<subview_col<eT>, op_htrans> >
  : public quasi_unwrap_subview_col_htrans_redirect< Op<subview_col<eT>, op_htrans>, is_cx<eT>::value >::result
  {
  typedef typename quasi_unwrap_subview_col_htrans_redirect< Op<subview_col<eT>, op_htrans>, is_cx<eT>::value >::result quasi_unwrap_subview_col_htrans_extra;
  
  inline
  quasi_unwrap(const Op<subview_col<eT>, op_htrans>& A)
    : quasi_unwrap_subview_col_htrans_extra(A)
    {
    }
  
  static constexpr bool is_const     = quasi_unwrap_subview_col_htrans_extra::is_const;
  static constexpr bool has_subview  = quasi_unwrap_subview_col_htrans_extra::has_subview;
  static constexpr bool has_orig_mem = quasi_unwrap_subview_col_htrans_extra::has_orig_mem;
  
  using quasi_unwrap_subview_col_htrans_extra::M;
  using quasi_unwrap_subview_col_htrans_extra::is_alias;
  };



template<typename T1>
struct quasi_unwrap< CubeToMatOp<T1, op_vectorise_cube_col> >
  {
  typedef typename T1::elem_type eT;
  
  inline
  quasi_unwrap(const CubeToMatOp<T1, op_vectorise_cube_col>& A)
    : U( A.m )
    , M( const_cast<eT*>(U.M.memptr()), U.M.n_elem, 1, false, true )
    {
    arma_debug_sigprint();
    }
  
  const unwrap_cube<T1> U;
  const Mat<eT>         M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  };



template<typename eT>
struct quasi_unwrap< SpToDOp<SpMat<eT>, op_sp_nonzeros> >
  {
  inline
  quasi_unwrap(const SpToDOp<SpMat<eT>, op_sp_nonzeros>& A)
    : orig( A.m )
    , M( const_cast<eT*>(orig.values), orig.n_nonzero, 1, false, true )
    {
    arma_debug_sigprint();
    }
  
  const SpMat<eT>& orig;
  const Mat<eT>    M;
  
  static constexpr bool is_const     = true;
  static constexpr bool has_subview  = true;
  static constexpr bool has_orig_mem = true;
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  };



//
//
//



template<typename T1>
struct unwrap_check_default
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  unwrap_check_default(const T1& A, const Mat<eT>&)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  inline
  unwrap_check_default(const T1& A, const bool)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT> M;
  };



template<typename T1>
struct unwrap_check_fixed
  {
  typedef typename T1::elem_type eT;
  typedef T1                     stored_type;
  
  inline
  unwrap_check_fixed(const T1& A, const Mat<eT>& B)
    : M_local( (&A == &B) ? new T1(A) : nullptr )
    , M      ( (&A == &B) ? *M_local  : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  unwrap_check_fixed(const T1& A, const bool is_alias)
    : M_local( is_alias ? new T1(A) : nullptr )
    , M      ( is_alias ? *M_local  : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  ~unwrap_check_fixed()
    {
    arma_debug_sigprint();
    
    if(M_local) { delete M_local; }
    }
  
  
  // the order below is important
  const T1* M_local;
  const T1& M;
  };



template<typename T1, bool condition>
struct unwrap_check_redirect {};

template<typename T1>
struct unwrap_check_redirect<T1, false> { typedef unwrap_check_default<T1> result; };

template<typename T1>
struct unwrap_check_redirect<T1, true>  { typedef unwrap_check_fixed<T1>   result; };


template<typename T1>
struct unwrap_check : public unwrap_check_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  inline unwrap_check(const T1& A, const Mat<typename T1::elem_type>& B)
    : unwrap_check_redirect<T1, is_Mat_fixed<T1>::value>::result(A, B)
    {
    }
  
  inline unwrap_check(const T1& A, const bool is_alias)
    : unwrap_check_redirect<T1, is_Mat_fixed<T1>::value>::result(A, is_alias)
    {
    }
  };



template<typename eT>
struct unwrap_check< Mat<eT> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  unwrap_check(const Mat<eT>& A, const Mat<eT>& B)
    : M_local( (&A == &B) ? new Mat<eT>(A) : nullptr )
    , M      ( (&A == &B) ? (*M_local)     : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  unwrap_check(const Mat<eT>& A, const bool is_alias)
    : M_local( is_alias ? new Mat<eT>(A) : nullptr )
    , M      ( is_alias ? (*M_local)     : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  ~unwrap_check()
    {
    arma_debug_sigprint();
    
    if(M_local) { delete M_local; }
    }
  
  
  // the order below is important
  const Mat<eT>* M_local;
  const Mat<eT>& M;
  };



template<typename eT>
struct unwrap_check< Row<eT> >
  {
  typedef Row<eT> stored_type;
  
  inline
  unwrap_check(const Row<eT>& A, const Mat<eT>& B)
    : M_local( (&A == &B) ? new Row<eT>(A) : nullptr )
    , M      ( (&A == &B) ? (*M_local)     : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  unwrap_check(const Row<eT>& A, const bool is_alias)
    : M_local( is_alias ? new Row<eT>(A) : nullptr )
    , M      ( is_alias ? (*M_local)     : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  ~unwrap_check()
    {
    arma_debug_sigprint();
    
    if(M_local) { delete M_local; }
    }
  
  
  // the order below is important
  const Row<eT>* M_local;
  const Row<eT>& M;
  };



template<typename eT>
struct unwrap_check< Col<eT> >
  {
  typedef Col<eT> stored_type;
  
  inline
  unwrap_check(const Col<eT>& A, const Mat<eT>& B)
    : M_local( (&A == &B) ? new Col<eT>(A) : nullptr )
    , M      ( (&A == &B) ? (*M_local)     : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  unwrap_check(const Col<eT>& A, const bool is_alias)
    : M_local( is_alias ? new Col<eT>(A) : nullptr )
    , M      ( is_alias ? (*M_local)     : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  ~unwrap_check()
    {
    arma_debug_sigprint();
    
    if(M_local) { delete M_local; }
    }
  
  
  // the order below is important
  const Col<eT>* M_local;
  const Col<eT>& M;
  };



//
//
//



template<typename T1>
struct unwrap_check_mixed
  {
  typedef typename T1::elem_type eT1;
  
  template<typename eT2>
  inline
  unwrap_check_mixed(const T1& A, const Mat<eT2>&)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  //template<typename eT2>
  inline
  unwrap_check_mixed(const T1& A, const bool)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT1> M;
  };



template<typename eT1>
struct unwrap_check_mixed< Mat<eT1> >
  {
  template<typename eT2>
  inline
  unwrap_check_mixed(const Mat<eT1>& A, const Mat<eT2>& B)
    : M_local( ((is_same_type<eT1,eT2>::yes) && (void_ptr(&A) == void_ptr(&B))) ? new Mat<eT1>(A) : nullptr )
    , M      ( ((is_same_type<eT1,eT2>::yes) && (void_ptr(&A) == void_ptr(&B))) ? (*M_local)      : A       )
    {
    arma_debug_sigprint();
    }
  
  //template<typename eT2>
  inline
  unwrap_check_mixed(const Mat<eT1>& A, const bool is_alias)
    : M_local( is_alias ? new Mat<eT1>(A) : nullptr )
    , M      ( is_alias ? (*M_local)      : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  ~unwrap_check_mixed()
    {
    arma_debug_sigprint();
    
    if(M_local) { delete M_local; }
    }
  
  
  // the order below is important
  const Mat<eT1>* M_local;
  const Mat<eT1>& M;
  };



template<typename eT1>
struct unwrap_check_mixed< Row<eT1> >
  {
  template<typename eT2>
  inline
  unwrap_check_mixed(const Row<eT1>& A, const Mat<eT2>& B)
    : M_local( ((is_same_type<eT1,eT2>::yes) && (void_ptr(&A) == void_ptr(&B))) ? new Row<eT1>(A) : nullptr )
    , M      ( ((is_same_type<eT1,eT2>::yes) && (void_ptr(&A) == void_ptr(&B))) ? (*M_local)      : A       )
    {
    arma_debug_sigprint();
    }
  
  
  //template<typename eT2>
  inline
  unwrap_check_mixed(const Row<eT1>& A, const bool is_alias)
    : M_local( is_alias ? new Row<eT1>(A) : nullptr )
    , M      ( is_alias ? (*M_local)      : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  ~unwrap_check_mixed()
    {
    arma_debug_sigprint();
    
    if(M_local) { delete M_local; }
    }
  
  
  // the order below is important
  const Row<eT1>* M_local;
  const Row<eT1>& M;
  };



template<typename eT1>
struct unwrap_check_mixed< Col<eT1> >
  {
  template<typename eT2>
  inline
  unwrap_check_mixed(const Col<eT1>& A, const Mat<eT2>& B)
    : M_local( ((is_same_type<eT1,eT2>::yes) && (void_ptr(&A) == void_ptr(&B))) ? new Col<eT1>(A) : nullptr )
    , M      ( ((is_same_type<eT1,eT2>::yes) && (void_ptr(&A) == void_ptr(&B))) ? (*M_local)      : A       )
    {
    arma_debug_sigprint();
    }
  
  //template<typename eT2>
  inline
  unwrap_check_mixed(const Col<eT1>& A, const bool is_alias)
    : M_local( is_alias ? new Col<eT1>(A) : nullptr )
    , M      ( is_alias ? (*M_local)      : A       )
    {
    arma_debug_sigprint();
    }
  
  inline
  ~unwrap_check_mixed()
    {
    arma_debug_sigprint();
    
    if(M_local) { delete M_local; }
    }
  
  
  // the order below is important
  const Col<eT1>* M_local;
  const Col<eT1>& M;
  };



//
//
//



template<typename T1>
struct partial_unwrap_default
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  partial_unwrap_default(const T1& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = false;
  
  const Mat<eT> M;
  };


template<typename T1>
struct partial_unwrap_fixed
  {
  typedef typename T1::elem_type eT;
  typedef T1                     stored_type;
  
  inline explicit
  partial_unwrap_fixed(const T1& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const T1& M;
  };



template<typename T1, bool condition>
struct partial_unwrap_redirect {};

template<typename T1>
struct partial_unwrap_redirect<T1, false> { typedef partial_unwrap_default<T1> result; };

template<typename T1>
struct partial_unwrap_redirect<T1, true>  { typedef partial_unwrap_fixed<T1>   result; };

template<typename T1>
struct partial_unwrap : public partial_unwrap_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  inline
  partial_unwrap(const T1& A)
    : partial_unwrap_redirect< T1, is_Mat_fixed<T1>::value>::result(A)
    {
    }
  };



template<typename eT>
struct partial_unwrap< Mat<eT> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const Mat<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Row<eT> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const Row<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Row<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Col<eT> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const Col<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Col<eT>& M;
  };



template<typename eT>
struct partial_unwrap< subview<eT> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const subview<eT>& A)
    : sv( A                                                  )
    , M ( A, ((A.aux_row1 == 0) && (A.n_rows == A.m.n_rows)) )  // reuse memory if the subview is a contiguous chunk
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return ( ((sv.aux_row1 == 0) && (sv.n_rows == sv.m.n_rows)) ? (void_ptr(&(sv.m)) == void_ptr(&X)) : false ); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = false;  // can't determine at compile time that memory is reused
  
  const subview<eT>& sv;
  const Mat<eT>      M;
  };



template<typename eT>
struct partial_unwrap< subview_col<eT> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const subview_col<eT>& A)
    : orig( A.m )
    , M   ( const_cast<eT*>( A.colmem ), A.n_rows, false, false )
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&orig)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  const Col<eT>  M;
  };



template<typename eT>
struct partial_unwrap< subview_cols<eT> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const subview_cols<eT>& A)
    : orig( A.m )
    , M   ( const_cast<eT*>( A.colptr(0) ), A.n_rows, A.n_cols, false, false )
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&orig)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  const Mat<eT>  M;
  };



template<typename eT>
struct partial_unwrap< subview_row<eT> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const subview_row<eT>& A)
    : sv( A                    )
    , M ( A, (A.m.n_rows == 1) )
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (sv.m.n_rows == 1) ? (void_ptr(&X) == void_ptr(&(sv.m))) : false; }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = false;  // can't determine at compile time that memory is reused
  
  const subview_row<eT>& sv;
  const Row<eT>          M;
  };



template<typename T1>
struct partial_unwrap_htrans_default
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  partial_unwrap_htrans_default(const Op<T1, op_htrans>& A)
    : M(A.m)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = false;
  
  const Mat<eT> M;
  };


template<typename T1>
struct partial_unwrap_htrans_fixed
  {
  typedef typename T1::elem_type eT;
  typedef T1                     stored_type;
  
  inline explicit
  partial_unwrap_htrans_fixed(const Op<T1, op_htrans>& A)
    : M(A.m)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const T1& M;
  };



template<typename T1, bool condition>
struct partial_unwrap_htrans_redirect {};

template<typename T1>
struct partial_unwrap_htrans_redirect<T1, false> { typedef partial_unwrap_htrans_default<T1> result; };

template<typename T1>
struct partial_unwrap_htrans_redirect<T1, true>  { typedef partial_unwrap_htrans_fixed<T1>   result; };

template<typename T1>
struct partial_unwrap< Op<T1, op_htrans> > : public partial_unwrap_htrans_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  inline partial_unwrap(const Op<T1, op_htrans>& A)
    : partial_unwrap_htrans_redirect<T1, is_Mat_fixed<T1>::value>::result(A)
    {
    }
  };



template<typename eT>
struct partial_unwrap< Op< Mat<eT>, op_htrans> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const Op< Mat<eT>, op_htrans>& A)
    : M(A.m)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Op< Row<eT>, op_htrans> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const Op< Row<eT>, op_htrans>& A)
    : M(A.m)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Row<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Op< Col<eT>, op_htrans> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const Op< Col<eT>, op_htrans>& A)
    : M(A.m)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Col<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Op< subview<eT>, op_htrans> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview<eT>, op_htrans>& A)
    : sv( A.m                                                        )
    , M ( A.m, ((A.m.aux_row1 == 0) && (A.m.n_rows == A.m.m.n_rows)) )  // reuse memory if the subview is a contiguous chunk
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return ( ((sv.aux_row1 == 0) && (sv.n_rows == sv.m.n_rows)) ? (void_ptr(&(sv.m)) == void_ptr(&X)) : false ); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = false;  // can't determine at compile time that memory is reused
  
  const subview<eT>& sv;
  const Mat<eT>      M;
  };



template<typename eT>
struct partial_unwrap< Op< subview_cols<eT>, op_htrans> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview_cols<eT>, op_htrans>& A)
    : orig( A.m.m )
    , M   ( const_cast<eT*>( A.m.colptr(0) ), A.m.n_rows, A.m.n_cols, false, false )
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&orig) == void_ptr(&X)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  const Mat<eT>  M;
  };



template<typename eT>
struct partial_unwrap< Op< subview_col<eT>, op_htrans> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview_col<eT>, op_htrans>& A)
    : orig( A.m.m )
    , M   ( const_cast<eT*>( A.m.colmem ), A.m.n_rows, false, false )
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&orig)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  const Col<eT>  M;
  };



template<typename eT>
struct partial_unwrap< Op< subview_row<eT>, op_htrans> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview_row<eT>, op_htrans>& A)
    : M(A.m)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(1); }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = false;
  static constexpr bool is_fast  = false;
  
  const Row<eT> M;
  };



template<typename T1>
struct partial_unwrap_htrans2_default
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  partial_unwrap_htrans2_default(const Op<T1, op_htrans2>& A)
    : val(A.aux)
    , M  (A.m)
    {
    arma_debug_sigprint();
    }
  
  arma_inline eT get_val() const { return val; }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = false;
  
  const eT      val;
  const Mat<eT> M;
  };


template<typename T1>
struct partial_unwrap_htrans2_fixed
  {
  typedef typename T1::elem_type eT;
  typedef T1                     stored_type;
  
  inline explicit
  partial_unwrap_htrans2_fixed(const Op<T1, op_htrans2>& A)
    : val(A.aux)
    , M  (A.m)
    {
    arma_debug_sigprint();
    }
  
  arma_inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT  val;
  const T1& M;
  };



template<typename T1, bool condition>
struct partial_unwrap_htrans2_redirect {};

template<typename T1>
struct partial_unwrap_htrans2_redirect<T1, false> { typedef partial_unwrap_htrans2_default<T1> result; };

template<typename T1>
struct partial_unwrap_htrans2_redirect<T1, true>  { typedef partial_unwrap_htrans2_fixed<T1>   result; };

template<typename T1>
struct partial_unwrap< Op<T1, op_htrans2> > : public partial_unwrap_htrans2_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  inline partial_unwrap(const Op<T1, op_htrans2>& A)
    : partial_unwrap_htrans2_redirect<T1, is_Mat_fixed<T1>::value>::result(A)
    {
    }
  };



template<typename eT>
struct partial_unwrap< Op< Mat<eT>, op_htrans2> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const Op< Mat<eT>, op_htrans2>& A)
    : val(A.aux)
    , M  (A.m)
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT       val;
  const Mat<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Op< Row<eT>, op_htrans2> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const Op< Row<eT>, op_htrans2>& A)
    : val(A.aux)
    , M  (A.m)
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT       val;
  const Row<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Op< Col<eT>, op_htrans2> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const Op< Col<eT>, op_htrans2>& A)
    : val(A.aux)
    , M  (A.m)
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT       val;
  const Col<eT>& M;
  };



template<typename eT>
struct partial_unwrap< Op< subview<eT>, op_htrans2> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview<eT>, op_htrans2>& A)
    : sv ( A.m   )
    , val( A.aux )
    , M  ( A.m, ((A.m.aux_row1 == 0) && (A.m.n_rows == A.m.m.n_rows)) )  // reuse memory if the subview is a contiguous chunk
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return ( ((sv.aux_row1 == 0) && (sv.n_rows == sv.m.n_rows)) ? (void_ptr(&(sv.m)) == void_ptr(&X)) : false ); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = false;  // can't determine at compile time that memory is reused
  
  const subview<eT>& sv;
  const eT           val;
  const Mat<eT>      M;
  };



template<typename eT>
struct partial_unwrap< Op< subview_cols<eT>, op_htrans2> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview_cols<eT>, op_htrans2>& A)
    : orig( A.m.m )
    , val ( A.aux )
    , M   ( const_cast<eT*>( A.m.colptr(0) ), A.m.n_rows, A.m.n_cols, false, false )
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&orig) == void_ptr(&X)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  const eT       val;
  const Mat<eT>  M;
  };



template<typename eT>
struct partial_unwrap< Op< subview_col<eT>, op_htrans2> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview_col<eT>, op_htrans2>& A)
    : orig( A.m.m )
    , val ( A.aux )
    , M   ( const_cast<eT*>( A.m.colmem ), A.m.n_rows, false, false )
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&orig)); }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  
  const eT      val;
  const Col<eT> M;
  };



template<typename eT>
struct partial_unwrap< Op< subview_row<eT>, op_htrans2> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const Op< subview_row<eT>, op_htrans2>& A)
    : val(A.aux)
    , M  (A.m  )
    {
    arma_debug_sigprint();
    }
  
  arma_inline eT get_val() const { return val; }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = true;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = false;
  
  const eT      val;
  const Row<eT> M;
  };



template<typename T1>
struct partial_unwrap_scalar_times_default
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  partial_unwrap_scalar_times_default(const eOp<T1, eop_scalar_times>& A)
    : val(A.aux)
    , M  (A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  arma_inline eT get_val() const { return val; }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = false;
  
  const eT      val;
  const Mat<eT> M;
  };



template<typename T1>
struct partial_unwrap_scalar_times_fixed
  {
  typedef typename T1::elem_type eT;
  typedef T1                     stored_type;
  
  inline explicit
  partial_unwrap_scalar_times_fixed(const eOp<T1, eop_scalar_times>& A)
    : val(A.aux)
    , M  (A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  arma_inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT  val;
  const T1& M;
  };



template<typename T1, bool condition>
struct partial_unwrap_scalar_times_redirect {};

template<typename T1>
struct partial_unwrap_scalar_times_redirect<T1, false> { typedef partial_unwrap_scalar_times_default<T1> result; };

template<typename T1>
struct partial_unwrap_scalar_times_redirect<T1, true>  { typedef partial_unwrap_scalar_times_fixed<T1>   result; };


template<typename T1>
struct partial_unwrap< eOp<T1, eop_scalar_times> > : public partial_unwrap_scalar_times_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  typedef typename T1::elem_type eT;
  
  inline
  partial_unwrap(const eOp<T1, eop_scalar_times>& A)
    : partial_unwrap_scalar_times_redirect< T1, is_Mat_fixed<T1>::value>::result(A)
    {
    }
  };



template<typename eT>
struct partial_unwrap< eOp<Mat<eT>, eop_scalar_times> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<Mat<eT>,eop_scalar_times>& A)
    : val(A.aux)
    , M  (A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT       val;
  const Mat<eT>& M;
  };



template<typename eT>
struct partial_unwrap< eOp<Row<eT>, eop_scalar_times> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<Row<eT>,eop_scalar_times>& A)
    : val(A.aux)
    , M  (A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT       val;
  const Row<eT>& M;
  };



template<typename eT>
struct partial_unwrap< eOp<Col<eT>, eop_scalar_times> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<Col<eT>,eop_scalar_times>& A)
    : val(A.aux)
    , M  (A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const eT       val;
  const Col<eT>& M;
  };



template<typename eT>
struct partial_unwrap< eOp<subview_col<eT>, eop_scalar_times> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<subview_col<eT>,eop_scalar_times>& A)
    : orig( A.P.Q.m )
    , val ( A.aux   )
    , M   ( const_cast<eT*>( A.P.Q.colmem ), A.P.Q.n_rows, false, false )
    {
    arma_debug_sigprint();
    }
  
  arma_inline eT get_val() const { return val; }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&orig)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  
  const eT      val;
  const Col<eT> M;
  };



template<typename eT>
struct partial_unwrap< eOp<subview_row<eT>, eop_scalar_times> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<subview_row<eT>,eop_scalar_times>& A)
    : val(A.aux)
    , M  (A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  arma_inline eT get_val() const { return val; }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = false;
  
  const eT      val;
  const Row<eT> M;
  };



template<typename T1>
struct partial_unwrap_neg_default
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  partial_unwrap_neg_default(const eOp<T1, eop_neg>& A)
    : M(A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(-1); }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = false;
  
  const Mat<eT> M;
  };



template<typename T1>
struct partial_unwrap_neg_fixed
  {
  typedef typename T1::elem_type eT;
  typedef T1                     stored_type;
  
  inline explicit
  partial_unwrap_neg_fixed(const eOp<T1, eop_neg>& A)
    : M(A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(-1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const T1& M;
  };



template<typename T1, bool condition>
struct partial_unwrap_neg_redirect {};

template<typename T1>
struct partial_unwrap_neg_redirect<T1, false> { typedef partial_unwrap_neg_default<T1> result; };

template<typename T1>
struct partial_unwrap_neg_redirect<T1, true>  { typedef partial_unwrap_neg_fixed<T1>   result; };


template<typename T1>
struct partial_unwrap< eOp<T1, eop_neg> > : public partial_unwrap_neg_redirect<T1, is_Mat_fixed<T1>::value>::result
  {
  typedef typename T1::elem_type eT;
  
  inline
  partial_unwrap(const eOp<T1, eop_neg>& A)
    : partial_unwrap_neg_redirect< T1, is_Mat_fixed<T1>::value>::result(A)
    {
    }
  };



template<typename eT>
struct partial_unwrap< eOp<Mat<eT>, eop_neg> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<Mat<eT>,eop_neg>& A)
    : M(A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(-1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& M;
  };



template<typename eT>
struct partial_unwrap< eOp<Row<eT>, eop_neg> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<Row<eT>,eop_neg>& A)
    : M(A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(-1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const Row<eT>& M;
  };



template<typename eT>
struct partial_unwrap< eOp<Col<eT>, eop_neg> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<Col<eT>,eop_neg>& A)
    : M(A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(-1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&M)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const Col<eT>& M;
  };



template<typename eT>
struct partial_unwrap< eOp<subview_col<eT>, eop_neg> >
  {
  typedef Col<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<subview_col<eT>,eop_neg>& A)
    : orig( A.P.Q.m )
    , M   ( const_cast<eT*>( A.P.Q.colmem ), A.P.Q.n_rows, false, false )
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(-1); }
  
  template<typename eT2>
  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&X) == void_ptr(&orig)); }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = true;
  
  const Mat<eT>& orig;
  const Col<eT>  M;
  };



template<typename eT>
struct partial_unwrap< eOp<subview_row<eT>, eop_neg> >
  {
  typedef Row<eT> stored_type;
  
  inline
  partial_unwrap(const eOp<subview_row<eT>,eop_neg>& A)
    : M(A.P.Q)
    {
    arma_debug_sigprint();
    }
  
  constexpr eT get_val() const { return eT(-1); }
  
  template<typename eT2>
  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
  
  static constexpr bool do_trans = false;
  static constexpr bool do_times = true;
  static constexpr bool is_fast  = false;
  
  const Row<eT> M;
  };



//
//
//



template<typename T1>
struct sv_keep_unwrap
  {
  typedef typename T1::elem_type eT;
  typedef Mat<eT>                stored_type;
  
  inline
  sv_keep_unwrap(const T1& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT> M;
  };



template<typename eT>
struct sv_keep_unwrap< subview<eT> >
  {
  typedef subview<eT> stored_type;
  
  inline
  sv_keep_unwrap(const subview<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const subview<eT>& M;
  };



template<typename eT>
struct sv_keep_unwrap< subview_row<eT> >
  {
  typedef subview_row<eT> stored_type;
  
  inline
  sv_keep_unwrap(const subview_row<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const subview_row<eT>& M;
  };



template<typename eT>
struct sv_keep_unwrap< subview_col<eT> >
  {
  typedef subview_col<eT> stored_type;
  
  inline
  sv_keep_unwrap(const subview_col<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const subview_col<eT>& M;
  };



template<typename eT>
struct sv_keep_unwrap< Mat<eT> >
  {
  typedef Mat<eT> stored_type;
  
  inline
  sv_keep_unwrap(const Mat<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Mat<eT>& M;
  };



template<typename eT>
struct sv_keep_unwrap< Row<eT> >
  {
  typedef Row<eT> stored_type;
  
  inline
  sv_keep_unwrap(const Row<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Row<eT>& M;
  };



template<typename eT>
struct sv_keep_unwrap< Col<eT> >
  {
  typedef Col<eT> stored_type;
  
  inline
  sv_keep_unwrap(const Col<eT>& A)
    : M(A)
    {
    arma_debug_sigprint();
    }
  
  const Col<eT>& M;
  };



//! @}
