text: #pragma once
  
  #include <Core/Block.h>
  
  
  namespace DB
  {
  
  /** Column, that is just group of few another columns.
    *
    * For constant Tuples, see ColumnConst.
    * Mixed constant/non-constant columns is prohibited in tuple
    *  for implementation simplicity.
    */
  class ColumnTuple final : public COWHelper<IColumn, ColumnTuple>
  {
  private:
      friend class COWHelper<IColumn, ColumnTuple>;
  
      using TupleColumns = std::vector<WrappedPtr>;
      TupleColumns columns;
  
      template <bool positive>
      struct Less;
  
      explicit ColumnTuple(MutableColumns && columns);
      ColumnTuple(const ColumnTuple &) = default;
  
  public:
      /** Create immutable column using immutable arguments. This arguments may be shared with other columns.
        * Use IColumn::mutate in order to make mutable column and mutate shared nested columns.
        */
      using Base = COWHelper<IColumn, ColumnTuple>;
      static Ptr create(const Columns & columns);
      static Ptr create(const TupleColumns & columns);
      static Ptr create(Columns && arg) { return create(arg); }
  
      template <typename Arg, typename = typename std::enable_if<std::is_rvalue_reference<Arg &&>::value>::type>
      static MutablePtr create(Arg && arg) { return Base::create(std::forward<Arg>(arg)); }
  
      std::string getName() const override;
      const char * getFamilyName() const override { return "Tuple"; }
  
      MutableColumnPtr cloneEmpty() const override;
      MutableColumnPtr cloneResized(size_t size) const override;
  
      size_t size() const override
      {
          return columns.at(0)->size();
      }
  
      Field operator[](size_t n) const override;
      void get(size_t n, Field & res) const override;
  
      StringRef getDataAt(size_t n) const override;
      void insertData(const char * pos, size_t length) override;
      void insert(const Field & x) override;
      void insertFrom(const IColumn & src_, size_t n) override;
      void insertDefault() override;
      void popBack(size_t n) override;
      StringRef serializeValueIntoArena(size_t n, Arena & arena, char const *& begin) const override;
      const char * deserializeAndInsertFromArena(const char * pos) override;
      void updateHashWithValue(size_t n, SipHash & hash) const override;
      void updateWeakHash32(WeakHash32 & hash) const override;
      void insertRangeFrom(const IColumn & src, size_t start, size_t length) override;
      ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
      ColumnPtr permute(const Permutation & perm, size_t limit) const override;
      ColumnPtr index(const IColumn & indexes, size_t limit) const override;
      ColumnPtr replicate(const Offsets & offsets) const override;
      MutableColumns scatter(ColumnIndex num_columns, const Selector & selector) const override;
      void gather(ColumnGathererStream & gatherer_stream) override;
      int compareAt(size_t n, size_t m, const IColumn & rhs, int nan_direction_hint) const override;
      void getExtremes(Field & min, Field & max) const override;
      void getPermutation(bool reverse, size_t limit, int nan_direction_hint, Permutation & res) const override;
      void reserve(size_t n) override;
      size_t byteSize() const override;
      size_t allocatedBytes() const override;
      void protect() override;
      void forEachSubcolumn(ColumnCallback callback) override;
      bool structureEquals(const IColumn & rhs) const override;
  
      size_t tupleSize() const { return columns.size(); }
  
      const IColumn & getColumn(size_t idx) const { return *columns[idx]; }
      IColumn & getColumn(size_t idx) { return *columns[idx]; }
  
      const TupleColumns & getColumns() const { return columns; }
      Columns getColumnsCopy() const { return {columns.begin(), columns.end()}; }
  
      const ColumnPtr & getColumnPtr(size_t idx) const { return columns[idx]; }
  };
  
  
  }
  