// 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 subview_elem2
//! @{



template<typename eT, typename T1, typename T2>
class subview_elem2 : public Base< eT, subview_elem2<eT,T1,T2> >
  {
  public:    
  
  typedef eT                                       elem_type;
  typedef typename get_pod_type<elem_type>::result pod_type;
  
  static constexpr bool is_row  = false;
  static constexpr bool is_col  = false;
  static constexpr bool is_xvec = false;
  
  arma_aligned const Mat<eT>& m;
  
  arma_aligned const Base<uword,T1>& base_ri;
  arma_aligned const Base<uword,T2>& base_ci;
  
  const bool all_rows;
  const bool all_cols;
  
  
  protected:
  
  arma_inline subview_elem2(const Mat<eT>& in_m, const Base<uword,T1>& in_ri, const Base<uword,T2>& in_ci, const bool in_all_rows, const bool in_all_cols);
  
  
  public:
  
  inline ~subview_elem2();
  inline  subview_elem2() = delete;
  
  template<typename op_type>
  inline void inplace_op(const eT val);
  
  template<typename op_type, typename expr>
  inline void inplace_op(const Base<eT,expr>& x);
  
  inline void replace(const eT old_val, const eT new_val);
  
  inline void clean(const pod_type threshold);
  
  inline void clamp(const eT min_val, const eT max_val);
  
  inline void fill(const eT val);
  inline void zeros();
  inline void ones();
  inline void randu();
  inline void randn();
  
  inline void operator+= (const eT val);
  inline void operator-= (const eT val);
  inline void operator*= (const eT val);
  inline void operator/= (const eT val);
  
  
  // deliberately returning void
  template<typename T3, typename T4> inline void operator_equ(const subview_elem2<eT,T3,T4>& x);
  template<typename T3, typename T4> inline void operator=   (const subview_elem2<eT,T3,T4>& x);
                                     inline void operator=   (const subview_elem2<eT,T1,T2>& x);
  
  template<typename T3, typename T4> inline void operator+=  (const subview_elem2<eT,T3,T4>& x);
  template<typename T3, typename T4> inline void operator-=  (const subview_elem2<eT,T3,T4>& x);
  template<typename T3, typename T4> inline void operator%=  (const subview_elem2<eT,T3,T4>& x);
  template<typename T3, typename T4> inline void operator/=  (const subview_elem2<eT,T3,T4>& x);
  
  template<typename expr> inline void operator=  (const Base<eT,expr>& x);
  template<typename expr> inline void operator+= (const Base<eT,expr>& x);
  template<typename expr> inline void operator-= (const Base<eT,expr>& x);
  template<typename expr> inline void operator%= (const Base<eT,expr>& x);
  template<typename expr> inline void operator/= (const Base<eT,expr>& x);
  
  template<typename expr> inline void operator=  (const SpBase<eT,expr>& x);
  template<typename expr> inline void operator+= (const SpBase<eT,expr>& x);
  template<typename expr> inline void operator-= (const SpBase<eT,expr>& x);
  template<typename expr> inline void operator%= (const SpBase<eT,expr>& x);
  template<typename expr> inline void operator/= (const SpBase<eT,expr>& x);
  
  inline static void extract(Mat<eT>& out, const subview_elem2& in);
  
  inline static void  plus_inplace(Mat<eT>& out, const subview_elem2& in);
  inline static void minus_inplace(Mat<eT>& out, const subview_elem2& in);
  inline static void schur_inplace(Mat<eT>& out, const subview_elem2& in);
  inline static void   div_inplace(Mat<eT>& out, const subview_elem2& in);
  
  template<typename eT2>
  inline bool is_alias(const Mat<eT2>& X) const;
  
  
  friend class Mat<eT>;
  };



//! @}
