doc/getfem_reference/gmm__ref_8h_source.html

/* -*- c++ -*- (enables emacs c++ mode) */

/*===========================================================================


 Copyright (C) 2000-2020 Yves Renard


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 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

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 Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.


 As a special exception, you  may use  this file  as it is a part of a free

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===========================================================================*/


#ifndef GMM_REF_H__

#define GMM_REF_H__


/** @file gmm_ref.h

   @author  Yves Renard <Yves.Renard@insa-lyon.fr>

   @date August 26, 2000.

 *  @brief Provide some simple pseudo-containers.

 *

 *  WARNING : modifiying the container infirm the validity of references.

 */


#include <iterator>

#include "gmm_except.h"


namespace gmm {


  /* ********************************************************************* */

  /* Simple reference.                                                     */

  /* ********************************************************************* */


  template<typename ITER> class tab_ref {


    protected :


      ITER begin_, end_;


    public :


      typedef typename std::iterator_traits<ITER>::value_type  value_type;

      typedef typename std::iterator_traits<ITER>::pointer     pointer;

      typedef typename std::iterator_traits<ITER>::pointer     const_pointer;

      typedef typename std::iterator_traits<ITER>::reference   reference;

      typedef typename std::iterator_traits<ITER>::reference   const_reference;

      typedef typename std::iterator_traits<ITER>::difference_type

                                                               difference_type;

      typedef ITER                            iterator;

      typedef ITER                            const_iterator;

      typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

      typedef std::reverse_iterator<iterator> reverse_iterator;

      typedef size_t size_type;


      bool empty(void) const { return begin_ == end_; }

      size_type size(void) const { return end_ - begin_; }


      const iterator &begin(void) { return begin_; }

      const const_iterator &begin(void) const { return begin_; }

      const iterator &end(void) { return end_; }

      const const_iterator &end(void) const { return end_; }

      reverse_iterator rbegin(void) { return reverse_iterator(end()); }

      const_reverse_iterator rbegin(void) const

      { return const_reverse_iterator(end()); }

      reverse_iterator rend(void) { return reverse_iterator(begin()); }

      const_reverse_iterator rend(void) const

      { return const_reverse_iterator(begin()); }


      reference front(void) { return *begin(); }

      const_reference front(void) const { return *begin(); }

      reference back(void) { return *(--(end())); }

      const_reference back(void) const { return *(--(end())); }

      void pop_front(void) { ++begin_; }


      const_reference operator [](size_type ii) const { return *(begin_ + ii);}

      reference operator [](size_type ii) { return *(begin_ + ii); }


      tab_ref(void) {}

      tab_ref(const ITER &b, const ITER &e) : begin_(b), end_(e) {}

  };


  /* ********************************************************************* */

  /* Reference with index.                                                 */

  /* ********************************************************************* */


//   template<typename ITER> struct tab_ref_index_iterator_

//     : public dynamic_array<size_t>::const_iterator

//   {

//     typedef typename std::iterator_traits<ITER>::value_type  value_type;

//     typedef typename std::iterator_traits<ITER>::pointer     pointer;

//     typedef typename std::iterator_traits<ITER>::reference   reference;

//     typedef typename std::iterator_traits<ITER>::difference_type

//     difference_type;

//     typedef std::random_access_iterator_tag iterator_category;

//     typedef size_t size_type;

//     typedef dynamic_array<size_type>::const_iterator dnas_iterator_;

//     typedef tab_ref_index_iterator_<ITER> iterator;


//     ITER piter;


//     iterator operator ++(int)

//     { iterator tmp = *this; ++(*((dnas_iterator_ *)(this))); return tmp; }

//     iterator operator --(int)

//     { iterator tmp = *this; --(*((dnas_iterator_ *)(this))); return tmp; }

//     iterator &operator ++()

//     { ++(*((dnas_iterator_ *)(this))); return *this; }

//     iterator &operator --()

//     { --(*((dnas_iterator_ *)(this))); return *this; }

//     iterator &operator +=(difference_type i)

//     { (*((dnas_iterator_ *)(this))) += i; return *this; }

//     iterator &operator -=(difference_type i)

//     { (*((dnas_iterator_ *)(this))) -= i; return *this; }

//     iterator operator +(difference_type i) const

//     { iterator it = *this; return (it += i); }

//     iterator operator -(difference_type i) const

//     { iterator it = *this; return (it -= i); }

//     difference_type operator -(const iterator &i) const

//     { return *((dnas_iterator_ *)(this)) - *((dnas_iterator_ *)(&i)); }


//     reference operator *() const

//     { return *(piter + *((*((dnas_iterator_ *)(this))))); }

//     reference operator [](int ii)

//     { return *(piter + *((*((dnas_iterator_ *)(this+ii))))); }


//     bool operator ==(const iterator &i) const

//     {

//       return ((piter) == ((i.piter))

//        && *((dnas_iterator_ *)(this)) == *((*((dnas_iterator_ *)(this)))));

//     }

//     bool operator !=(const iterator &i) const

//     { return !(i == *this); }

//     bool operator < (const iterator &i) const

//     {

//       return ((piter) == ((i.piter))

//       && *((dnas_iterator_ *)(this)) < *((*((dnas_iterator_ *)(this)))));

//     }


//     tab_ref_index_iterator_(void) {}

//     tab_ref_index_iterator_(const ITER &iter, const dnas_iterator_ &dnas_iter)

//       : dnas_iterator_(dnas_iter), piter(iter) {}

//   };


//   template<typename ITER> class tab_ref_index

//   {

//     public :


//       typedef typename std::iterator_traits<ITER>::value_type value_type;

//       typedef typename std::iterator_traits<ITER>::pointer    pointer;

//       typedef typename std::iterator_traits<ITER>::pointer    const_pointer;

//       typedef typename std::iterator_traits<ITER>::reference  reference;

//       typedef typename std::iterator_traits<ITER>::reference  const_reference;

//       typedef typename std::iterator_traits<ITER>::difference_type

//                                                             difference_type;

//       typedef size_t size_type;

//       typedef tab_ref_index_iterator_<ITER> iterator;

//       typedef iterator                          const_iterator;

//       typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

//       typedef std::reverse_iterator<iterator> reverse_iterator;


//     protected :


//       ITER begin_;

//       dynamic_array<size_type> index_;


//     public :


//       bool empty(void) const { return index_.empty(); }

//       size_type size(void) const { return index_.size(); }


//       iterator begin(void) { return iterator(begin_, index_.begin()); }

//       const_iterator begin(void) const

//       { return iterator(begin_, index_.begin()); }

//       iterator end(void) { return iterator(begin_, index_.end()); }

//       const_iterator end(void) const { return iterator(begin_, index_.end()); }

//       reverse_iterator rbegin(void) { return reverse_iterator(end()); }

//       const_reverse_iterator rbegin(void) const

//       { return const_reverse_iterator(end()); }

//       reverse_iterator rend(void) { return reverse_iterator(begin()); }

//       const_reverse_iterator rend(void) const

//       { return const_reverse_iterator(begin()); }


//       reference front(void) { return *(begin_ +index_[0]); }

//       const_reference front(void) const { return *(begin_ +index_[0]); }

//       reference back(void) { return *(--(end())); }

//       const_reference back(void) const { return *(--(end())); }


//       tab_ref_index(void) {}

//       tab_ref_index(const ITER &b, const dynamic_array<size_type> &ind)

//       { begin_ = b; index_ = ind; }


//     // to be changed in a const_reference ?

//       value_type operator [](size_type ii) const

//       { return *(begin_ + index_[ii]);}

//       reference operator [](size_type ii) { return *(begin_ + index_[ii]); }


//   };


  /// iterator over a gmm::tab_ref_index_ref<ITER,ITER_INDEX>

  template<typename ITER, typename ITER_INDEX>

    struct tab_ref_index_ref_iterator_

    {

      typedef typename std::iterator_traits<ITER>::value_type value_type;

      typedef typename std::iterator_traits<ITER>::pointer    pointer;

      typedef typename std::iterator_traits<ITER>::reference  reference;

      typedef typename std::iterator_traits<ITER>::difference_type

                                                              difference_type;

      typedef std::random_access_iterator_tag iterator_category;

      typedef tab_ref_index_ref_iterator_<ITER, ITER_INDEX> iterator;

      typedef size_t size_type;


      ITER piter;

      ITER_INDEX iter_index;


      iterator operator ++(int)

      { iterator tmp = *this; ++iter_index; return tmp; }

      iterator operator --(int)

      { iterator tmp = *this; --iter_index; return tmp; }

      iterator &operator ++() { ++iter_index; return *this; }

      iterator &operator --() { --iter_index; return *this; }

      iterator &operator +=(difference_type i)

      { iter_index += i; return *this; }

      iterator &operator -=(difference_type i)

      { iter_index -= i; return *this; }

      iterator operator +(difference_type i) const

      { iterator it = *this; return (it += i); }

      iterator operator -(difference_type i) const

      { iterator it = *this; return (it -= i); }

      difference_type operator -(const iterator &i) const

      { return iter_index - i.iter_index; }


      reference operator *() const

      { return *(piter + *iter_index); }

      reference operator [](size_type ii) const

      { return *(piter + *(iter_index+ii)); }


      bool operator ==(const iterator &i) const

      { return ((piter) == ((i.piter)) && iter_index == i.iter_index); }

      bool operator !=(const iterator &i) const { return !(i == *this); }

      bool operator < (const iterator &i) const

      { return ((piter) == ((i.piter)) && iter_index < i.iter_index); }


      tab_ref_index_ref_iterator_(void) {}

      tab_ref_index_ref_iterator_(const ITER &iter,

                                  const ITER_INDEX &dnas_iter)

        : piter(iter), iter_index(dnas_iter) {}


    };


  /**

      convenience template function for quick obtention of a indexed iterator

      without having to specify its (long) typename

  */

  template<typename ITER, typename ITER_INDEX>

  tab_ref_index_ref_iterator_<ITER,ITER_INDEX>

  index_ref_iterator(ITER it, ITER_INDEX it_i) {

    return tab_ref_index_ref_iterator_<ITER,ITER_INDEX>(it, it_i);

  }


  /** indexed array reference (given a container X, and a set of indexes I,

      this class provides a pseudo-container Y such that

      @code Y[i] = X[I[i]] @endcode

  */

  template<typename ITER, typename ITER_INDEX> class tab_ref_index_ref {

  public :


    typedef std::iterator_traits<ITER>            traits_type;

    typedef typename traits_type::value_type      value_type;

    typedef typename traits_type::pointer         pointer;

    typedef typename traits_type::pointer         const_pointer;

    typedef typename traits_type::reference       reference;

    typedef typename traits_type::reference       const_reference;

    typedef typename traits_type::difference_type difference_type;

    typedef size_t                                size_type;

    typedef tab_ref_index_ref_iterator_<ITER, ITER_INDEX>   iterator;

    typedef iterator                              const_iterator;

    typedef std::reverse_iterator<const_iterator>     const_reverse_iterator;

    typedef std::reverse_iterator<iterator>           reverse_iterator;


  protected :


    ITER begin_;

    ITER_INDEX index_begin_, index_end_;


  public :


    bool empty(void) const { return index_begin_ == index_end_; }

    size_type size(void) const { return index_end_ - index_begin_; }


    iterator begin(void) { return iterator(begin_, index_begin_); }

    const_iterator begin(void) const

    { return iterator(begin_, index_begin_); }

    iterator end(void) { return iterator(begin_, index_end_); }

    const_iterator end(void) const { return iterator(begin_, index_end_); }

    reverse_iterator rbegin(void) { return reverse_iterator(end()); }

    const_reverse_iterator rbegin(void) const

    { return const_reverse_iterator(end()); }

    reverse_iterator rend(void) { return reverse_iterator(begin()); }

    const_reverse_iterator rend(void) const

    { return const_reverse_iterator(begin()); }


    reference front(void) { return *(begin_ + *index_begin_); }

    const_reference front(void) const { return *(begin_ + *index_begin_); }

    reference back(void) { return *(--(end())); }

    const_reference back(void) const { return *(--(end())); }

    void pop_front(void) { ++index_begin_; }


    tab_ref_index_ref(void) {}

    tab_ref_index_ref(const ITER &b, const ITER_INDEX &bi,

                      const ITER_INDEX &ei)

      : begin_(b), index_begin_(bi), index_end_(ei) {}


    // to be changed in a const_reference ?

    const_reference operator [](size_type ii) const

    { return *(begin_ + index_begin_[ii]);}

    reference operator [](size_type ii)

    { return *(begin_ + index_begin_[ii]); }


  };


  /* ********************************************************************* */

  /* Reference on regularly spaced elements.                               */

  /* ********************************************************************* */


  template<typename ITER> struct tab_ref_reg_spaced_iterator_ {


    typedef typename std::iterator_traits<ITER>::value_type value_type;

    typedef typename std::iterator_traits<ITER>::pointer    pointer;

    typedef typename std::iterator_traits<ITER>::reference  reference;

    typedef typename std::iterator_traits<ITER>::difference_type

                                                            difference_type;

    typedef typename std::iterator_traits<ITER>::iterator_category

                                                            iterator_category;

    typedef size_t size_type;

    typedef tab_ref_reg_spaced_iterator_<ITER> iterator;


    ITER it;

    size_type N, i;


    iterator operator ++(int) { iterator tmp = *this; i++; return tmp; }

    iterator operator --(int) { iterator tmp = *this; i--; return tmp; }

    iterator &operator ++()   { i++; return *this; }

    iterator &operator --()   { i--; return *this; }

    iterator &operator +=(difference_type ii) { i+=ii; return *this; }

    iterator &operator -=(difference_type ii) { i-=ii; return *this; }

    iterator operator +(difference_type ii) const

    { iterator itt = *this; return (itt += ii); }

    iterator operator -(difference_type ii) const

    { iterator itt = *this; return (itt -= ii); }

    difference_type operator -(const iterator &ii) const

    { return (N ? (it - ii.it) / N : 0) + i - ii.i; }


    reference operator *() const { return *(it + i*N); }

    reference operator [](size_type ii) const { return *(it + (i+ii)*N); }


    bool operator ==(const iterator &ii) const

    { return (*this - ii) == difference_type(0); }

    bool operator !=(const iterator &ii) const

    { return  (*this - ii) != difference_type(0); }

    bool operator < (const iterator &ii) const

    { return (*this - ii) < difference_type(0); }


    tab_ref_reg_spaced_iterator_(void) {}

    tab_ref_reg_spaced_iterator_(const ITER &iter, size_type n, size_type ii)

      : it(iter), N(n), i(ii) { }


  };


  /**

      convenience template function for quick obtention of a strided iterator

      without having to specify its (long) typename

  */

  template<typename ITER> tab_ref_reg_spaced_iterator_<ITER>

  reg_spaced_iterator(ITER it, size_t stride) {

    return tab_ref_reg_spaced_iterator_<ITER>(it, stride);

  }


  /**

     provide a "strided" view a of container

  */

  template<typename ITER> class tab_ref_reg_spaced {

  public :


    typedef typename std::iterator_traits<ITER>::value_type value_type;

    typedef typename std::iterator_traits<ITER>::pointer    pointer;

    typedef typename std::iterator_traits<ITER>::pointer    const_pointer;

    typedef typename std::iterator_traits<ITER>::reference  reference;

    typedef typename std::iterator_traits<ITER>::reference  const_reference;

    typedef typename std::iterator_traits<ITER>::difference_type

            difference_type;

    typedef size_t size_type;

    typedef tab_ref_reg_spaced_iterator_<ITER> iterator;

    typedef iterator                          const_iterator;

    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

    typedef std::reverse_iterator<iterator> reverse_iterator;


  protected :


    ITER begin_;

    size_type N, size_;


  public :


    bool empty(void) const { return size_ == 0; }

    size_type size(void) const { return size_; }


    iterator begin(void) { return iterator(begin_, N, 0); }

    const_iterator begin(void) const { return iterator(begin_, N, 0); }

    iterator end(void) { return iterator(begin_, N, size_); }

    const_iterator end(void) const { return iterator(begin_, N, size_); }

    reverse_iterator rbegin(void) { return reverse_iterator(end()); }

    const_reverse_iterator rbegin(void) const

    { return const_reverse_iterator(end()); }

    reverse_iterator rend(void) { return reverse_iterator(begin()); }

    const_reverse_iterator rend(void) const

    { return const_reverse_iterator(begin()); }


    reference front(void) { return *begin_; }

    const_reference front(void) const { return *begin_; }

    reference back(void) { return *(begin_ + N * (size_-1)); }

    const_reference back(void) const { return *(begin_ + N * (size_-1)); }

    void pop_front(void) { begin_ += N; }


    tab_ref_reg_spaced(void) {}

    tab_ref_reg_spaced(const ITER &b, size_type n, size_type s)

      : begin_(b), N(n), size_(s) {}


    const_reference operator [](size_type ii) const

    { return *(begin_ + ii * N);}

    reference operator [](size_type ii) { return *(begin_ + ii * N); }


  };


  /// iterator over a tab_ref_with_selection

  template<typename ITER, typename COND>

  struct tab_ref_with_selection_iterator_ : public ITER {

    typedef typename std::iterator_traits<ITER>::value_type value_type;

    typedef typename std::iterator_traits<ITER>::pointer    pointer;

    typedef typename std::iterator_traits<ITER>::reference  reference;

    typedef typename std::iterator_traits<ITER>::difference_type

                                                              difference_type;

    typedef std::forward_iterator_tag iterator_category;

    typedef tab_ref_with_selection_iterator_<ITER, COND> iterator;

    const COND cond;


    void forward(void) { while (!(cond)(*this)) ITER::operator ++(); }

    iterator &operator ++()

    { ITER::operator ++(); forward(); return *this; }

    iterator operator ++(int)

    { iterator tmp = *this; ++(*this); return tmp; }


    tab_ref_with_selection_iterator_(void) {}

    tab_ref_with_selection_iterator_(const ITER &iter, const COND c)

      : ITER(iter), cond(c) {}


  };


  /**

     given a container X and a predicate P, provide pseudo-container Y

     of all elements of X such that P(X[i]).

  */

  template<typename ITER, typename COND> class tab_ref_with_selection {


  protected :


    ITER begin_, end_;

    COND cond;


  public :


    typedef typename std::iterator_traits<ITER>::value_type value_type;

    typedef typename std::iterator_traits<ITER>::pointer    pointer;

    typedef typename std::iterator_traits<ITER>::pointer    const_pointer;

    typedef typename std::iterator_traits<ITER>::reference  reference;

    typedef typename std::iterator_traits<ITER>::reference  const_reference;

    typedef size_t  size_type;

    typedef tab_ref_with_selection_iterator_<ITER, COND> iterator;

    typedef iterator   const_iterator;


    iterator begin(void) const

    { iterator it(begin_, cond); it.forward(); return it; }

    iterator end(void) const { return iterator(end_, cond); }

    bool empty(void) const { return begin_ == end_; }


    value_type front(void) const { return *begin(); }

    void pop_front(void) { ++begin_; begin_ = begin(); }


    COND &condition(void) { return cond; }

    const COND &condition(void) const { return cond; }


    tab_ref_with_selection(void) {}

    tab_ref_with_selection(const ITER &b, const ITER &e, const COND &c)

      : begin_(b), end_(e), cond(c) { begin_ = begin(); }


  };


}


#endif /* GMM_REF_H__  */