include/o3tl/enumarray.hxx

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  19
  20 #ifndef INCLUDED_O3TL_ENUMARRAY_HXX
  21 #define INCLUDED_O3TL_ENUMARRAY_HXX
  22
  23 #include <sal/config.h>
  24 #include <iterator>
  25
  26 namespace o3tl {
  27
  28 template<typename EA>
  29 class enumarray_iterator;
  30
  31 ///
  32 /// This is a container convenience class for arrays indexed by enum values.
  33 ///
  34 /// This assumes that the 'enum class' definition
  35 ///  - starts at zero
  36 ///  - has no holes in it's sequence of values
  37 ///  - defines a value called LAST which refers to the greatest constant.
  38 ///
  39 /// \param E the 'enum class' type.
  40 /// \param V the value type to be stored in the array
  41 template<typename E, typename V>
  42 class enumarray SAL_FINAL
  43 {
  44 public:
  45     typedef enumarray<E, V> self_type;
  46     typedef enumarray_iterator<self_type> iterator;
  47
  48     typedef V             value_type;
  49     typedef E             key_type;
  50     typedef size_t        size_type;
  51
  52     static const size_type max_index = static_cast<size_type>(E::LAST);
  53
  54     const V& operator[](E index) const
  55     {
  56         assert(index>=static_cast<E>(0) && index<=E::LAST);
  57         return detail_values[static_cast<size_type>(index)];
  58     }
  59
  60     V& operator[](E index)
  61     {
  62         assert(index>=static_cast<E>(0) && index<=E::LAST);
  63         return detail_values[static_cast<size_type>(index)];
  64     }
  65
  66     void fill(V val)
  67     { for (size_type i=0; i<=max_index; ++i) detail_values[i] = val; }
  68
  69     static size_type size() { return max_index + 1; }
  70     iterator  begin()      { return iterator(*this, 0); }
  71     iterator  end()        { return iterator(*this, size()); }
  72
  73     V*        data()       { return detail_values; }
  74
  75 //private:
  76     V detail_values[max_index + 1];
  77 };
  78
  79
  80 template<typename EA>
  81 class enumarray_iterator {
  82     EA         *m_buf;
  83     size_t      m_pos;
  84 public:
  85     typedef enumarray_iterator<EA>  self_type;
  86     typedef typename EA::value_type value_type;
  87     typedef typename EA::key_type   key_type;
  88     typedef std::bidirectional_iterator_tag iterator_category; //should be random access, but that would require define subtraction operators on the enums
  89     typedef typename EA::key_type   difference_type;
  90     typedef typename EA::value_type*   pointer;
  91     typedef typename EA::value_type&   reference;
  92
  93     enumarray_iterator(EA& b, size_t start_pos)
  94          : m_buf(&b), m_pos(start_pos) {}
  95     value_type &operator*()  { return (*m_buf)[static_cast<key_type>(m_pos)]; }
  96     value_type *operator->() { return &(operator*()); }
  97     self_type  &operator++() { ++m_pos; return *this; }
  98     bool        operator!=(const self_type& other) { return m_buf != other.m_buf || m_pos != other.m_pos; }
  99     bool        operator==(const self_type& other) { return m_buf == other.m_buf && m_pos == other.m_pos; }
 100 };
 101
 102 }; // namespace o3tl
 103
 104 #endif /* INCLUDED_O3TL_ENUMARRAY_HXX */
 105
 106 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */