// 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 access
//! @{


struct access
  {
  //! internal function to allow modification of data declared as read-only (use with caution)
  template<typename T1>   static constexpr T1&  rw (const T1& x)        { return const_cast<T1& >(x); }
  template<typename T1>   static constexpr T1*& rwp(const T1* const& x) { return const_cast<T1*&>(x); }
  
  //! internal function to obtain the real part of either a plain number or a complex number
  template<typename eT>   static constexpr const eT& tmp_real(const eT&              X) { return X;        }
  template<typename  T>   static constexpr const   T tmp_real(const std::complex<T>& X) { return X.real(); }
  
  //! internal function to obtain the imag part of either a plain number or a complex number
  template<typename eT>   static constexpr const eT tmp_imag(const eT                ) { return eT(0);    }
  template<typename  T>   static constexpr const  T tmp_imag(const std::complex<T>& X) { return X.imag(); }
  
  //! internal function to work around braindead compilers
  template<typename eT>   static constexpr const typename enable_if2<is_cx<eT>::no,  const eT&>::result alt_conj(const eT& X) { return X;            }
  template<typename eT> arma_inline static const typename enable_if2<is_cx<eT>::yes, const eT >::result alt_conj(const eT& X) { return std::conj(X); }
  };


//! @}