compiler doesn't recognize my friend

Hi all,

Code:

---


#include "CallbackTimer.h" // declares callbackfun

namespace nsScheduler{

class Scheduler : boost::noncopyable
{
        friend class Job;
        friend class WorkerThread;
        friend VOID CALLBACK callbackfun( PVOID param, BOOLEAN timer_or_wait_fired );
      //I want to allow that function access to member function onTimerTick()

      void onTimerTick();
      //.....
public:
      //...
};

}//namespace

---

Code:

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//CallbackTimer.h

VOID CALLBACK callbackfun( PVOID param, BOOLEAN timer_or_wait_fired );

namespace nsScheduler{

class Scheduler;

class CallbackTimer :boost::noncopyable
{
//...
}



//CallbackTimer.cpp

#include "CallbackTimer.h"

#include "Scheduler.h"

namespace nsScheduler{

//...
}

VOID CALLBACK
callbackfun( PVOID param, BOOLEAN timer_or_wait_fired )
{
        ( (nsScheduler::Scheduler*)param)->onTimerTick();
}

---

but MSVC says:

Quote:

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.\CallbackTimer.cpp(48) : error C2248: 'nsScheduler::Scheduler::onTimerTick' : cannot access private member declared in class 'nsScheduler::Scheduler'

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Does anybody has an idea why my friend decleration is ignored?

Thank you in advance!

It would be good if you posted the smallest and simplest program that demonstrates the error.

Well I had a linker that didn't recognize my uncle, but that's a whole different problem

here it is

Code:

---

#define _WIN32_WINNT 0x0500

#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#undef WIN32_LEAN_AND_MEAN

VOID CALLBACK callbackfun( PVOID param, BOOLEAN timer_or_wait_fired );

namespace nsScheduler{

        class Scheduler;

        class CallbackTimer
        {

                Scheduler& mrScheduler;

        public:

                CallbackTimer( Scheduler& scheduler )
                        :mrScheduler(scheduler)
                {}
        };

class Scheduler
{
        friend VOID CALLBACK callbackfun( PVOID param, BOOLEAN timer_or_wait_fired );

        void onTimerTick()
        {}
};

}//ns

VOID CALLBACK
callbackfun( PVOID param, BOOLEAN timer_or_wait_fired )
{
        ( (nsScheduler::Scheduler*)param)->onTimerTick();
}

int main()
{}

---

Quote:

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------ Build started: Project: TestProg, Configuration: Debug Win32 ------
Compiling...
main.cpp
c:\workspace-eclipse\testprog\testprog\main.cpp(23) : warning C4512: 'nsScheduler::CallbackTimer' : assignment operator could not be generated
c:\workspace-eclipse\testprog\testprog\main.cpp(14) : see declaration of 'nsScheduler::CallbackTimer'
c:\workspace-eclipse\testprog\testprog\main.cpp(38) : error C2248: 'nsScheduler::Scheduler::onTimerTick' : cannot access private member declared in class 'nsScheduler::Scheduler'
c:\workspace-eclipse\testprog\testprog\main.cpp(29) : see declaration of 'nsScheduler::Scheduler::onTimerTick'
c:\workspace-eclipse\testprog\testprog\main.cpp(26) : see declaration of 'nsScheduler::Scheduler'
Build log was saved at "file://c:\workspace-eclipse\TestProg\TestProg\Debug\BuildLog.htm"
TestProg - 1 error(s), 1 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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It's not clear from what you posted: you declare a friend function nsScheduler::callbackfun, and then declare a function ::callbackfun later?

hell,

Code:

---

class Scheduler
{
        friend VOID CALLBACK ::callbackfun( PVOID param, BOOLEAN timer_or_wait_fired );

---

did the trick.

thanks to brewbuck's uncle!

Indeed. Make it ::callbackfun in the friend declaration and it will work.


EDIT: Ah, late.

EDIT2: Well, the normative text about this was annoyingly hard to find, and in a highly unintuitive place. (In particular, it was neither in 3.4, name lookup, nor in 11.4, friends.)

Quote:

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Originally Posted by ISO C++ 2003, 7.3.1.2/3

When looking for a prior declaration of a class or a function declared as a friend, and when the name of the friend class or function is neither a qualified name nor a template-id, scopes outside the innermost enclosing namespace scope are not considered.

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