“没有适当的默认构造函数可用” - 为什么默认构造函数甚至被调用？

我已经看过关于这个的一些其他问题，但我不明白为什么一个默认的构造函数甚至应该在我的情况下调用。我可以提供一个默认的构造函数，但我想知道为什么它这样做和它影响。

I've looked at a few other questions about this, but I don't see why a default constructor should even be called in my case. I could just provide a default constructor, but I want to understand why it is doing this and what it affects.

error C2512: 'CubeGeometry' : no appropriate default constructor available  

我有一个名为ProxyPiece的类有CubeGeometry的成员变量。构造函数应该接受一个CubeGeometry并将其分配给成员变量。这是标题：

I have a class called ProxyPiece with a member variable of CubeGeometry.The constructor is supposed to take in a CubeGeometry and assign it to the member variable. Here is the header:

#pragma once
#include "CubeGeometry.h"

using namespace std;
class ProxyPiece
{
public:
    ProxyPiece(CubeGeometry& c);
    virtual ~ProxyPiece(void);
private:
    CubeGeometry cube;
};

和来源：

#include "StdAfx.h"
#include "ProxyPiece.h"

ProxyPiece::ProxyPiece(CubeGeometry& c)
{
    cube=c;
}


ProxyPiece::~ProxyPiece(void)
{
}

多维数据集几何的标题看起来像这样。我没有意义使用默认构造函数。我需要它吗？：

the header for cube geometry looks like this. It doesn't make sense to me to use a default constructor. Do I need it anyways?:

#pragma once
#include "Vector.h"
#include "Segment.h"
#include <vector>

using namespace std;

class CubeGeometry
{
public:
    CubeGeometry(Vector3 c, float l);

    virtual ~CubeGeometry(void);

    Segment* getSegments(){
        return segments;
    }

    Vector3* getCorners(){
        return corners;
    }

    float getLength(){
        return length;
    }

    void draw();

    Vector3 convertModelToTextureCoord (Vector3 modCoord) const;

    void setupCornersAndSegments();

private:
    //8 corners
    Vector3 corners[8];

    //and some segments
    Segment segments[12];

    Vector3 center;
    float length;
    float halfLength;
};