1 | #pragma once |
---|---|
2 | |
3 | #include <Columns/IColumnDummy.h> |
4 | |
5 | |
6 | namespace DB |
7 | { |
8 | |
9 | class ColumnNothing final : public COWHelper<IColumnDummy, ColumnNothing> |
10 | { |
11 | private: |
12 | friend class COWHelper<IColumnDummy, ColumnNothing>; |
13 | |
14 | ColumnNothing(size_t s_) |
15 | { |
16 | s = s_; |
17 | } |
18 | |
19 | ColumnNothing(const ColumnNothing &) = default; |
20 | |
21 | public: |
22 | const char * getFamilyName() const override { return "Nothing"; } |
23 | MutableColumnPtr cloneDummy(size_t s_) const override { return ColumnNothing::create(s_); } |
24 | |
25 | bool canBeInsideNullable() const override { return true; } |
26 | |
27 | bool structureEquals(const IColumn & rhs) const override |
28 | { |
29 | return typeid(rhs) == typeid(ColumnNothing); |
30 | } |
31 | }; |
32 | |
33 | } |
34 |