多重继承一个基类

这里是我的榜样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); 
};

而且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) {}

GCC回报：

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？一般概念是否正确？

来源

2015-01-12 just lerning

如果这是为了娱乐目的OK。但我强烈建议由于各种原因避免这种继承方案。 – 101010

在我看来，你的教授希望你探索虚拟基类问题 - 给出的名字非常暗示你画的那种钻石。 – Elemental

@Elemental我没有虚拟基础类的经验...我所有的尝试使用它们编译失败：（ –

通过

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

更换

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

当你有虚拟继承，只有一个virtual基类的实例。它必须在构造的最派生类的构造函数中进行初始化。

来源

2015-01-12 21:04:33

太棒了，真棒，谢谢！ –

我建议将Painting和Occupied的东西分成不同的类。因此，你可以有：

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

不想建立可怕的菱形继承。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。

来源

2015-01-12 20:20:42

来自JAVA背景，我想同意你的看法（尽管每个JAVA开发人员显然不喜欢多个遗产）。然而，类名（及其隐含的特征）是固定的，所以我不能重构任何东西。无论如何，谢谢你的建议！ –

多重继承一个基类

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