densevectorview.hh

// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
 
// SPDX-FileCopyrightText: Copyright © DUNE Project contributors, see file AUTHORS.md
// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception OR LGPL-3.0-or-later
 
#ifndef DUNE_FUNCTIONS_COMMON_DENSEVECTORVIEW_HH
#define DUNE_FUNCTIONS_COMMON_DENSEVECTORVIEW_HH
 
#include <type_traits>
 
#include <dune/common/densevector.hh>
 
 
namespace Dune::Functions::Impl {
 
  template<class R>
  class DenseVectorView
    : public DenseVector<DenseVectorView<R>>
  {
    R& data_;
 
    using mutable_reference = typename std::decay_t<R>::reference;
 
  public:
 
    using size_type = typename std::decay_t<R>::size_type;
 
    using value_type = typename std::decay_t<R>::value_type;
 
    using const_reference = typename std::decay_t<R>::const_reference;
 
    using reference = std::conditional_t<std::is_const_v<R>,
      const_reference,
      mutable_reference>;
 
    DenseVectorView (R& data)
      : data_(data)
    {}
 
    DenseVectorView (const DenseVectorView &other) = delete;
 
    DenseVectorView (DenseVectorView &&other) :
      data_( other.data_ )
    {}
 
    DenseVectorView& operator= (const DenseVectorView& other)
    {
      data_ = other.data_;
      return *this;
    }
 
    template<class RR>
    DenseVectorView& operator= (const DenseVectorView<RR>& other)
    {
      data_ = other.data_;
      return *this;
    }
 
    size_type size () const
    {
      return data_.size();
    }
 
    reference operator[] (size_type i)
    {
      return data_[i];
    }
 
    const_reference operator[] (size_type i) const
    {
      return data_[i];
    }
 
  }; // class DenseVectorView
 
}
 
namespace Dune {
 
  template< class R>
  struct DenseMatVecTraits< Dune::Functions::Impl::DenseVectorView<R> >
  {
    using derived_type = Dune::Functions::Impl::DenseVectorView<R>;
    using value_type = typename R::value_type;
    using size_type = typename R::size_type;
  };
 
  template< class R >
  struct FieldTraits< Dune::Functions::Impl::DenseVectorView<R> >
    : public FieldTraits<std::remove_const_t<typename Dune::Functions::Impl::DenseVectorView<R>::value_type>>
  {};
 
}
 
 
#endif // DUNE_FUNCTIONS_COMMON_DENSEVECTORVIEW_HH