python – swig错误：未定义的符号

我的错误是：

Traceback (most recent call last):
  File "./test1.py",line 5,in <module>
    from volumes import *
  File "/scratch/rjkern/projects/RJKERN_volrend/scripts/volumes.py",line 26,in <module>
    _volumes = swig_import_helper()
  File "/scratch/rjkern/projects/RJKERN_volrend/scripts/volumes.py",line 22,in swig_import_helper
    _mod = imp.load_module('_volumes',fp,pathname,description)
ImportError: /scratch/rjkern/projects/RJKERN_volrend/scripts/_volumes.so: undefined symbol: _ZN13ConstantColorC1ESt10shared_ptrI5ColorE

这是我的代码：

/*
 *  ColorOperations.h
 */

#ifndef ___COLOROPS___
#define ___COLOROPS___

#include "Color.h"
#include "ProgressMeter.h"
#include "Vector.h"
#include "Volume.h"
#include "VolumeOperations.h"

#include <memory>

using namespace std;

class ConstantColor : public Volume<Color>{
    shared_ptr <Color> color;

public:
    ConstantColor(const shared_ptr<Color>& _color);

    const Color eval(const Vector& P) const;
    Color grad(const Vector& P);
};
#endif

和：

/*
 *  ColorOperations.cpp
 */

#include "ColorOperations.h"

ConstantColor::ConstantColor(const shared_ptr<Color>& _color){
    color = _color;
}

const Color ConstantColor::eval(const Vector& P)const{
    return *color;
}