Trying to compile a .h file without understanding something

I'm trying to compile Opengazer (Open source gaze tracker) code with visual studio on windows, while the code was originally written for linux and should be compile with cmake.

Anyway, I can't compile few files.

The code won't compile is this:

Containers.h:

#pragma once

#define xforeachactive(iter,container) \
    for(typeof(container.begin()) iter = container.begin(); \
    iter != container.end(); iter++)            \
    if ((*iter)->parent == this)


template <class ParentType, class ChildType> class Container;

template <class ParentType, class ChildType> 
class  Containee {
 protected:
    void detach() { parent = 0; }
 public:
    ParentType *parent;     /* set to null to request removal */
    Containee(): parent(0) {}
    virtual ~Containee() {}
};

template <class ParentType, class ChildType>        
class Container {
    typedef ChildType *ChildPtr;
    static bool isFinished(const ChildPtr &object) { 
    return !(object && object->parent);
    }
 protected:
    std::vector<ChildPtr> objects;

    void removeFinished() { 
    objects.erase(remove_if(objects.begin(), objects.end(), isFinished),
              objects.end());
    }

 public:
    void clear() {
    xforeachactive(iter, objects)
        (*iter)->parent = 0;
    removeFinished();
    }


    static void addchild(ParentType *parent, const ChildPtr &child) {
    parent->objects.push_back(child);
    child->parent = parent;
    parent->removeFinished(); 
    }

    virtual ~Container() {
    clear();
    }
};

template <class ParentPtr, class ChildPtr>
class ProcessContainer: public Container<ParentPtr, ChildPtr> {
 public:
    virtual void process() {
    xforeachactive(iter, this->objects)
        (*iter)->process();
    this->removeFinished(); 
    }
    virtual ~ProcessContainer() {};
};

btw Containers.cpp is empty

ad the code uses the above class is:

#pragma once

class FrameProcessing;

class FrameFunction: 
public Containee<FrameProcessing, FrameFunction> 
{
    const int &frameno;
    int startframe;
 protected:
    int getFrame() { return frameno - startframe; }
public:
    FrameFunction(const int &frameno): frameno(frameno), startframe(frameno) {}
    virtual void process()=0;
    virtual ~FrameFunction();
};

class FrameProcessing: 
public ProcessContainer<FrameProcessing,FrameFunction> {};

class MovingTarget: public FrameFunction {
    WindowPointer *pointer;
 public:
    MovingTarget(const int &frameno, 
         const vector<Point>& points, 
         WindowPointer *&pointer,
         int dwelltime=20);
    virtual ~MovingTarget();
    virtual void process();
 protected:
    vector<Point> points;
    const int dwelltime;
    int getPointNo();
    int getPointFrame();
    bool active();
};

class CalibrationHandler
{
public:
    CalibrationHandler(void);
    ~CalibrationHandler(void);
};

the error I get is :

visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2146: syntax error : missing ';' before identifier 'iter'
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2065: 'iter' : undeclared identifier
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2065: 'iter' : undeclared identifier
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2146: syntax error : missing ')' before identifier 'iter'
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2059: syntax error : ';'
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2065: 'iter' : undeclared identifier
visual studio 2008\proj开发者_如何学运维ects\eyemouse\eyemouse\containers.h(58) : error C2059: syntax error : ')'
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2143: syntax error : missing ';' before 'if'
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2065: 'iter' : undeclared identifier
visual studio 2008\projects\eyemouse\eyemouse\containers.h(58) : error C2227: left of '->parent' must point to class/struct/union/generic type
        type is ''unknown-type''
visual studio 2008\projects\eyemouse\eyemouse\containers.h(59) : error C2065: 'iter' : undeclared identifier
visual studio 2008\projects\eyemouse\eyemouse\containers.h(59) : error C2227: left of '->process' must point to class/struct/union/generic type
        type is ''unknown-type''

I understand why I'm getting an error. 'iter' is not defined anywhere. anyway, this isnt my code and it should work. I tried to copy and past the define part to the function, but still get the same error. I'm stuck with this and trying to solve it for hours, but can't understand what to do to make it work.

I'll really be grateful for any help.

typeof is a gcc extension and equivalent to C++0x decltype there is no VS version that actually supports it.

You would need to use C++0x and decltype or try to use Boost.TypeOf, which comes with its own caveats.

Change the macro to this:

#include <boost/typeof/typeof.hpp>

#define xforeachactive(iter,container) \
    for(BOOST_TYPEOF(container.begin()) iter = container.begin(); \
    iter != container.end(); iter++)            \
    if ((*iter)->parent == this)

You could also use BOOST_AUTO if you think this is clearer.