我目前正在使用虚拟功能的用户程序。我只使用一个虚拟功能,并遇到了似乎是我尝试过的一个常见解决方案的常见问题,但不幸的是没有成功。未定义引用'typeinfo和'虚拟表
我最初有virtual void calcArea();在BasicShape.h中没有任何定义或指定为纯虚函数。我改变了它,并添加{}末(上有类似的问题,另一个线程的建议),但我仍然得到以下错误:
我输入:
g++ BasicShape.h BasicShape.cpp circle.h circle.cpp Rectangle.h Rectangle.cpp driver.cpp -o Lab4
然后我得到:
/tmp/ccf1Y4Br.o: In function `BasicShape::BasicShape()': circle.cpp:(.text._ZN10BasicShapeC2Ev[_ZN10BasicShapeC5Ev]+0xf): undefined reference to `vtable for BasicShape'
/tmp/ccf1Y4Br.o:(.rodata._ZTI6circle[_ZTI6circle]+0x10): undefined reference to `typeinfo for BasicShape'
/tmp/ccc7gjtH.o:(.rodata._ZTI9Rectangle[_ZTI9Rectangle]+0x10): undefined reference to `typeinfo for BasicShape'
collect2: error: ld returned 1 exit status
任何想法?
这是实现文件BasicShape.h:
#ifndef BASICSHAPE_H
#define BASICSHAPE_H
class BasicShape
{
protected:
double area;
public:
double getArea() const;
virtual void calcArea();
};
#endif
所附BasicShape.cpp文件:
#include "BasicShape.h"
double BasicShape::getArea() const
{
return area;
}
void BasicShape::calcArea()
{
}
circle.h:
#include "BasicShape.h"
#ifndef CIRCLE_H
#define CIRCLE_H
class circle : public BasicShape
{
private:
long centerX;
long centerY;
double radius;
public:
circle(long, long, double);
long getCenterX() const;
long getCenterY() const;
virtual void calcArea();
};
#endif
circle.cpp:
#include "circle.h"
// constructor
circle::circle(long userIn, long userIn2, double userIn3)
{
centerX = userIn;
centerY = userIn2;
radius = userIn3;
calcArea();
}
// accesors
long circle::getCenterX() const
{
return centerX;
}
long circle::getCenterY() const
{
return centerY;
}
// virtual function
void circle::calcArea()
{
area = (3.14159 * radius * radius);
}
Rectangle.h
#include "BasicShape.h"
#ifndef RECTANGLE_H
#define RECTANGLE_H
class Rectangle : public BasicShape
{
private:
long width;
long length;
public:
Rectangle(long, long);
long getWidth() const;
long getLength() const;
virtual void calcArea();
};
#endif
Rectangle.cpp:
#include "Rectangle.h"
// constructor
Rectangle::Rectangle(long userIn, long userIn2)
{
width = userIn;
length = userIn2;
calcArea();
}
// accessors
long Rectangle::getWidth() const
{
return width;
}
long Rectangle::getLength() const
{
return length;
}
void Rectangle::calcArea()
{
area = (length * width);
}
驱动程序是不完整的,但无关我的问题呢(至少我是这么认为的)。
#include <cassert>
#include <iostream>
#include "BasicShape.h"
#include "Rectangle.h"
#include "circle.h"
using namespace std;
int main()
{
cout << "Testing the functionality and efficiency of the circle class...\n";
// declare circle object and test accessors and area computation
circle objCircle(8,8,4);
assert(objCircle.getCenterX() == 8);
assert(objCircle.getCenterY() == 8);
assert(objCircle.getArea() == 50.26544);
cout << "Circle object testing completed successfully\n";
cout << "Testing the functionality and efficiency of the Rectangle class...\n";
// declare rectangle object and test accessors and area computation
//Rectangle objRec();
return 0;
}
恕我直言,你应该先试着说明你的完整问题(包括错误信息,你期望的等),然后用大量代码文件吓跑人们。 – congusbongus 2013-02-18 00:29:26
是的,它现在看起来有点威胁,现在我想到了它o_o thx的提示 – newwarrior21st 2013-02-18 00:31:54