4.9 sdds::RowView and sdds::RowMask

• name:
  sdds::RowView, sdds::RowMask
• description:
  Access a row without copying column storage and compose row selections. Masks support intersection, union, and inversion and can be produced by applying an untyped or exact-type predicate to a page column.
• synopsis:
  sdds::RowView Page::row(std::int64_t index) const;  
  std::int64_t RowView::index() const noexcept;  
  sdds::Scalar RowView::value(index-or-name) const;  
  template<class T> T RowView::get(std::string_view column) const;  
  template<class T> T RowView::getConverted(  
      std::string_view column, sdds::RoundingMode rounding = Reject) const;  
   
  explicit sdds::RowMask(std::size_t rows, bool selected = false);  
  static sdds::RowMask all(std::size_t rows);  
  static sdds::RowMask none(std::size_t rows);  
  std::size_t size() const noexcept;  
  std::size_t count() const noexcept;  
  bool test(std::size_t row) const;  
  void set(std::size_t row, bool selected = true);  
  RowMask &operator&=(const RowMask &other);  
  RowMask &operator|=(const RowMask &other);  
  RowMask operator~() const;

• arguments:
  • index, row — Zero-based row index.
  • column — Column index or name.
  • rows — Number of entries in a mask.
  • selected — Initial or replacement selection state.
  • other — Mask of identical size.
• return value:
  A row view, cell value, converted cell, mask status, or composed mask as appropriate. A RowView remains valid only while its source page remains alive and unmodified.
• exceptions:
  sdds::StateError for an unavailable column or mismatched mask sizes, or for an invalid row view; std::out_of_range for an invalid mask index; and the conversion exceptions described in Section 4.2.
• see also:
  Section 4.10.