部分代码：
class CLine
{
public:
    CLine(){}
    CLine(float X1=0,X2=0,Y1=0,Y2=0)
    {
        x1=X1;    x2=X2;  y1=Y1;  y2=Y2;
    }
    void Length()
    {
        int k;
        k= sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
        cout<<k<<endl;
    }
    void show()
    {
        cout<<'('<<x1<<','<<y1<<')'<<endl;
        cout<<'('<<x2<<','<<y2<<')'<<endl;
    }

private:
    float x1;
    float x2;
    float y1;
    float y2;
};



error C2629: unexpected 'class CLine ('；
error C2334: unexpected token(s) preceding '{'; skipping apparent function body；
这到底是哪儿出错了？？

谢谢大家，发现我还是没注意到好多小的知识点