一基多继承class

Question

（删除了原始文本，因为它与已经回答的当前问题无关。请参阅修订。）

这是我的例子test.hpp（简体）：

class House {
    private:
        int nWindows;
    public:
        House(int nWindows);
        int getNumberOfWindows();
};

class PaintedHouse : public virtual House {
    private:
        int colorCode;
    public:
        PaintedHouse(int nWindows, int colorCode);
        int getColorCode();
};

class OccupiedHouse : public virtual House {
    private:
        int nPeople;
    public:
        OccupiedHouse(int nWindows, int nPeople);
        int getNumberOfPeople();
};

class PaintedOccupiedHouse : public PaintedHouse, OccupiedHouse {
    public:
        PaintedOccupiedHouse(int nWindows, int colorCode, int nPeople);
};

和test.cpp：

#include "test.hpp"

House::House(int nWindows) { this->nWindows = nWindows; }
int House::getNumberOfWindows() { return this->nWindows; }

PaintedHouse::PaintedHouse(int nWindows, int colorCode) : House(nWindows) {
    this->colorCode = colorCode;
}
int PaintedHouse::getColorCode() { return this->colorCode; }

OccupiedHouse::OccupiedHouse(int nWindows, int nPeople) : House(nWindows) {
    this->nPeople = nPeople;
}
int OccupiedHouse::getNumberOfPeople() { return this->nPeople; }

PaintedOccupiedHouse::PaintedOccupiedHouse(int nWindows, int colorCode, int nPeople)
            : PaintedHouse(nWindows, colorCode), OccupiedHouse(nWindows, nPeople) {}

海湾合作委员会returns:

test.cpp: In constructor ‘PaintedOccupiedHouse::PaintedOccupiedHouse(int, int, int)’:
test.cpp:18:72: error: no matching function for call to ‘House::House()’
    : PaintedHouse(nWindows, colorCode), OccupiedHouse(nWindows, nPeople) {}
                                                                        ^
test.cpp:18:72: note: candidates are:
test.cpp:4:1: note: House::House(int)
 House::House(int nWindows) { this->nWindows = nWindows; }
 ^
test.cpp:4:1: note:   candidate expects 1 argument, 0 provided
In file included from test.cpp:2:0:
test.hpp:2:7: note: constexpr House::House(const House&)
 class House {
       ^
test.hpp:2:7: note:   candidate expects 1 argument, 0 provided
test.hpp:2:7: note: constexpr House::House(House&&)
test.hpp:2:7: note:   candidate expects 1 argument, 0 provided

你能告诉我我做错了什么吗？总体概念是否正确？

Answer 1

我建议将 Painting 和 Occupied 的内容分开类。因此你可以：

Painted    House   Occupied
   |         |        | 
   +---------+--------+  
             |  
  Painted_Occupied_House

不想设置可怕的钻石继承。看看你是否可以重构来缓解这个问题。

钻石界面带来了注入更多缺陷的可能性。

Answer 2

替换

PaintedOccupiedHouse::PaintedOccupiedHouse(int nWindows, int colorCode, int nPeople)
            : PaintedHouse(nWindows, colorCode), OccupiedHouse(nWindows, nPeople) {}

来自

PaintedOccupiedHouse::PaintedOccupiedHouse(int nWindows, int colorCode, int nPeople)
            : House(nWindows), PaintedHouse(nWindows, colorCode), OccupiedHouse(nWindows, nPeople) {}

当您拥有虚拟继承时，virtual 基础 class 只有一个实例。它必须在正在构造的最派生 class 的构造函数中初始化。

一基多继承class

Multiple inheritance with one base class

c++

inheritance

multiple-inheritance