C ++实验：如何改进这门课程？

Question

  

可能重复：
  How to Define or Implement C# Property in ISO C++?

我正在尝试编写一个可以在C ++中模拟C＃属性的类，我想出了下面的代码。它适用于POD类型（虽然声明语法当然不像C＃那样简洁），但是我想不出让getter返回除存储对象类型之外的东西的方法（同样，setter必须采用完全是存储的类型）。我希望能够指定一个返回（可能是const）引用的getter，而不是副本。当然，我想在编译时使用模板魔术来推断它，而不是为每个排列设置一个单独的类。

template<typename owner, typename propertyType, propertyType (owner::*getter)() const, void (owner::*setter)(propertyType)>
class property
{
    friend class property<owner, propertyType, getter, nullptr>;

private:
    owner &mOwner;

public:
    property(owner &owner)
        : mOwner(owner)
    {
    }

    template<typename otherProperty>
    property(const otherProperty &other)
        : mOwner(other.mOwner)
    {
    }

    property &operator=(const property &other)
    {
        assert(setter);
        (mOwner.*setter)((other.*)getter());
        return *this;
    }

    property &operator=(propertyType value)
    {
        assert(setter);
        (mOwner.*setter)(value);
        return *this;
    }

    template<typename otherProperty>
    property &operator=(const otherProperty &other)
    {
        assert(setter);
        (mOwner.*setter)(other);
        return *this;
    }

    operator propertyType() const
    {
        assert(getter);
        return (mOwner.*getter)();
    }
};

class Test
{
    typedef std::array<std::array<int, 4>, 4> array_type;
private:
    int mId;
    array_type mArray;

    int GetId() const;
    void SetId(int newId);

    // I would rather return a reference here, not a copy
    array_type GetArray() const;

public:
    property<Test, int, &GetId, &SetId> Id;
    property<Test, int, &GetId, nullptr> ReadOnlyId;

    // if GetArray returned a reference, this line would fail to compile
    property<Test, array_type, &GetArray, nullptr> Array;

public:
    Test()
        : mId(0)
        , Id(*this)
        , ReadOnlyId(Id)
        , Array(*this)
    {
    }
};