Functor Compilation Error

B

BSand0764

I'm getting an error that I can't seem to resolve. When I compile the
Functor related logic in a test program, the files compile and execute
properly (see Listing #1).

However, when I incorporate the same logic within my simulation, the
class that implements the functor logic has problems compiling. I get
the following errors:


-- Building myTest.cpp --
In file included from myTest.cpp:52:
.../tstDir/myFunctor.h:19: error: expected unqualified-id before '*'
token
.../tstDir/myFunctor.h:19: error: expected `)' before '*' token
.../tstDir/myFunctor.h:19: error: expected `,' or `...' before '*'
token
.../tstDir/myFunctor.h:19: error: `TSpecificFunctor' declared as
function returning a function
.../tstDir/myFunctor.h:19: error: `<anonymous>' has incomplete type
.../tstDir/myFunctor.h:19: error: invalid use of `void'
.../tstDir/myFunctor.h:19: error: expected `;' before ')' token
myTest.cpp: In member function `virtual void
tst::myTest::Initialize()':
myTest.cpp:527: error: no matching function for call to
`tst::TSpecificFunctor<tst::myScats>::TSpecificFunctor(tst::myScats*,
void (tst::myScats::*)())'
.../tstDir/myFunctor.h:14: note: candidates are:
tst::TSpecificFunctor<tst::myScats>::TSpecificFunctor(const
tst::TSpecificFunctor<tst::myScats>&)

Listing #2 provides the functor implementation as used in my
simulation. Can anyone tell me what is causing the compilation error
and how to possibly resolve it?

LISTING #2 (code in simulation)

In myTest.cpp:

#include "ScatFunctor.h"
#include "myScats.h"
#include "myFunctor.h"

void myTest::Initialize()
{
using namespace tst;

myScats objB;

TSpecificFunctor<myScats> specFunc( &objB, &myScats::Initialize);

myFunctor* funcTable[] = { &specFunc };

funcTable[0]->Call();
}


In myFunctor.h:

#ifndef myFunctor_H
#define myFunctor_H

#include "tst_config.h"

#include "ScatFunctor.h"

BEGIN_TST_NAMESPACE


template <class TClass> class TSpecificFunctor : public TFunctor
{
public:

// Constructor - takes pointer to an object and pointer to
// a member function and stores them in two private variables
TSpecificFunctor(TClass* _pt2Object, void(TClass::_*fpt) ())
{ pt2Object = _pt2Object; fpt = _fpt; };

// override function "call" in base class
virtual void Call()
{ (*pt2Object.*fpt) (); };

private:

void (TClass::*fpt) ();
TClass* pt2Object;
};

END_TST_NAMESPACE

#endif



In ScatFunctor.h:

#ifndef ScatFunctor_H
#define ScatFunctor_H

#include "tst_config.h"

BEGIN_TST_NAMESPACE

class TFunctor
{
public:

virtual void Call(); // call using function
};

END_TST_NAMESPACE

#endif


In myScats.h:

#ifndef myScats_H
#define myScats_H

#include "tst_config.h"

BEGIN_TST_NAMESPACE

class myScats
{
public:

// Constructor/Destructor
myScats() {};
virtual ~myScats();

void Initialize() {"In Scats Initialize"};

protected:

private:
};

END_TST_NAMESPACE

#endif // End of Listing #2



LISTING #1 (stand-alone test program)

In BaseFunctor.cpp:


#include "BaseFunctor.h"
#include "DerivedFunctor.h"
#include "sea.h"

int main (int argc, char* argv[])
{
sea objB;

// instantiate DerivedFunctor objects ...
// functor encapsulating pointer to object and to a member of
class sea
TSpecificFunctor<sea> specFuncSea(&objB, &sea::Display);

// array with pointers to the Base class (TFunctor) and initialize
it
TFunctor *vT = { &specFuncSea };

vT->Call();

return 0;
}


In BaseFunctor.h:

#ifndef BaseFunctor_H
#define BaseFunctor_H

// abstract base class

class TFunctor
{
public:

// Derived classes will use a pointer to an object and
// a pointer to a member function to make the function call
virtual void Call()=0; //call using provided function name
};

#endif


In DerivedFunctor.h:

#ifndef TSpecificFunctor_H
#define TSpecificFunctor_H

#include "BaseFunctor.h"


template <class TClass> class TSpecificFunctor : public TFunctor
{
public:

// Constructor - takes pointer to an object and pointer to
// a member function and stores them in two private variables

TSpecificFunctor(TClass* _pt2Object, void(TClass::*_fpt) ())
{ pt2Object = _pt2Object; fpt = _fpt; };

// override function "Call" in base class
virtual void Call() // executes member function
{ (*pt2Object.*fpt) (); };

private:

void (TClass::*fpt) (); // pointer to a member function
TClass* pt2Object; // pointer to an object
};

#endif



In Sea.h:

#ifndef sea_H
#define sea_H

#include <iostream>

using namespace std;

class sea
{
public:

sea() {};

// Sea's Functions
void Display() { cout << "In Sea Display" << endl; };

};

#endif



The above (LISTING #1) is compiled with the following script and
the resulting binary executes properly:

#/bin/sh

echo compiling C++ using -ansi -pedantic-errors -Wall -fPIC -g
g++ -ansi -pedantic-errors -Wall -Wno-deprecated -fPIC -g $1 $2 $3


Any help regarding some possible solutions for the compilation errors
would be greatly appreciated!

Danny
 
A

Alf P. Steinbach

* (e-mail address removed):
I'm getting an error that I can't seem to resolve. When I compile the
Functor related logic in a test program, the files compile and execute
properly (see Listing #1).

However, when I incorporate the same logic within my simulation, the
class that implements the functor logic has problems compiling. I get
the following errors:


-- Building myTest.cpp --
In file included from myTest.cpp:52:
../tstDir/myFunctor.h:19: error: expected unqualified-id before '*'
token
Click to expand...

If you look before the '*' token on line 19 of [myFunctor.h] you'll see
a single underscore, '_'.


[snip]
In Sea.h:

#ifndef sea_H
#define sea_H

#include <iostream>
Click to expand...

In general, don't include heavy standard library implementation headers
in header files.

using namespace std;
Click to expand...

Never have 'using namespace std;' in a header file. Never. Ever.

All code that includes this header, directly or indirectly, will have
its global namespace polluted with names from the standard library.

For example, client code may conceivable have its own global namespace
class called 'string'.

Cheers, & hth.,

- Alf
 
B

BSand0764

I'm getting an error that I can't seem to resolve. When I compile theFunctorrelated logic in a test program, the files compile and execute
properly (see Listing #1).

However, when I incorporate the same logic within my simulation, the
class that implements thefunctorlogic has problems compiling. I get
the following errors:

-- Building myTest.cpp --
In file included from myTest.cpp:52:
../tstDir/myFunctor.h:19: error: expected unqualified-id before '*'
token
../tstDir/myFunctor.h:19: error: expected `)' before '*' token
../tstDir/myFunctor.h:19: error: expected `,' or `...' before '*'
token
../tstDir/myFunctor.h:19: error: `TSpecificFunctor' declared as
function returning a function
../tstDir/myFunctor.h:19: error: `<anonymous>' has incomplete type
../tstDir/myFunctor.h:19: error: invalid use of `void'
../tstDir/myFunctor.h:19: error: expected `;' before ')' token
myTest.cpp: In member function `virtual void
tst::myTest::Initialize()':
myTest.cpp:527: error: no matching function for call to
`tst::TSpecificFunctor<tst::myScats>::TSpecificFunctor(tst::myScats*,
void (tst::myScats::*)())'
../tstDir/myFunctor.h:14: note: candidates are:
tst::TSpecificFunctor<tst::myScats>::TSpecificFunctor(const
tst::TSpecificFunctor<tst::myScats>&)

Listing #2 provides thefunctorimplementation as used in my
simulation. Can anyone tell me what is causing the compilation error
and how to possibly resolve it?

LISTING #2 (code in simulation)

In myTest.cpp:

#include "ScatFunctor.h"
#include "myScats.h"
#include "myFunctor.h"

void myTest::Initialize()
{
using namespace tst;

myScats objB;

TSpecificFunctor<myScats> specFunc( &objB, &myScats::Initialize);

myFunctor* funcTable[] = { &specFunc };

funcTable[0]->Call();

}

In myFunctor.h:

#ifndef myFunctor_H
#define myFunctor_H

#include "tst_config.h"

#include "ScatFunctor.h"

BEGIN_TST_NAMESPACE

template <class TClass> class TSpecificFunctor : public TFunctor
{
public:

// Constructor - takes pointer to an object and pointer to
// a member function and stores them in two private variables
TSpecificFunctor(TClass* _pt2Object, void(TClass::_*fpt) ())
{ pt2Object = _pt2Object; fpt = _fpt; };

// override function "call" in base class
virtual void Call()
{ (*pt2Object.*fpt) (); };

private:

void (TClass::*fpt) ();
TClass* pt2Object;

};

END_TST_NAMESPACE

#endif

In ScatFunctor.h:

#ifndef ScatFunctor_H
#define ScatFunctor_H

#include "tst_config.h"

BEGIN_TST_NAMESPACE

class TFunctor
{
public:

virtual void Call(); // call using function

};

END_TST_NAMESPACE

#endif

In myScats.h:

#ifndef myScats_H
#define myScats_H

#include "tst_config.h"

BEGIN_TST_NAMESPACE

class myScats
{
public:

// Constructor/Destructor
myScats() {};
virtual ~myScats();

void Initialize() {"In Scats Initialize"};

protected:

private:

};

END_TST_NAMESPACE

#endif // End of Listing #2

LISTING #1 (stand-alone test program)

In BaseFunctor.cpp:

#include "BaseFunctor.h"
#include "DerivedFunctor.h"
#include "sea.h"

int main (int argc, char* argv[])
{
sea objB;

// instantiate DerivedFunctor objects ...
//functorencapsulating pointer to object and to a member of
class sea
TSpecificFunctor<sea> specFuncSea(&objB, &sea::Display);

// array with pointers to the Base class (TFunctor) and initialize
it
TFunctor *vT = { &specFuncSea };

vT->Call();

return 0;

}

In BaseFunctor.h:

#ifndef BaseFunctor_H
#define BaseFunctor_H

// abstract base class

class TFunctor
{
public:

// Derived classes will use a pointer to an object and
// a pointer to a member function to make the function call
virtual void Call()=0; //call using provided function name

};

#endif

In DerivedFunctor.h:

#ifndef TSpecificFunctor_H
#define TSpecificFunctor_H

#include "BaseFunctor.h"

template <class TClass> class TSpecificFunctor : public TFunctor
{
public:

// Constructor - takes pointer to an object and pointer to
// a member function and stores them in two private variables

TSpecificFunctor(TClass* _pt2Object, void(TClass::*_fpt) ())
{ pt2Object = _pt2Object; fpt = _fpt; };

// override function "Call" in base class
virtual void Call() // executes member function
{ (*pt2Object.*fpt) (); };

private:

void (TClass::*fpt) (); // pointer to a member function
TClass* pt2Object; // pointer to an object

};

#endif

In Sea.h:

#ifndef sea_H
#define sea_H

#include <iostream>

using namespace std;

class sea
{
public:

sea() {};

// Sea's Functions
void Display() { cout << "In Sea Display" << endl; };

};

#endif

The above (LISTING #1) is compiled with the following script and
the resulting binary executes properly:

#/bin/sh

echo compiling C++ using -ansi -pedantic-errors -Wall -fPIC -g
g++ -ansi -pedantic-errors -Wall -Wno-deprecated -fPIC -g $1 $2 $3

Any help regarding some possible solutions for the compilation errors
would be greatly appreciated!

Danny
Click to expand...

Thanks Alf!! Your suggestions / tips worked great! However, I now
have a secondary problem if you or anyone else could help me with. I
have the following code:

#ifndef MYFUNCTOR_H
#define MYFUNCTOR_H

#include "struct1.h"
#include "struct2.h"

class MyFunctor
{
public:

// No arg list
virtual void Call()=0; // call using function

// For multi args
virtual void Call_m(struct1*, struct2*, int, double)=0;
};
#endif


#ifndef TSTFUNCTOR_H
#define TSTFUNCTOR_H

#include "MyFunctor.h"

template <class TClass> class TSpecificFunctor : public MyFunctor
{
public:

// Constructor - takes pointer to an object and pointer to
// a member function and stores them in two private variables

// no arg list
TSpecificFunctor( TClass* _pt2Object, void(TClass::*tfpt) ())
{ pt2Object = _pt2Object; fpt = tfpt; };

// For Multi Args
TSpecificFunctor( TClass* _pt2Object, void(TClass::*tfpt)
(struct1*, struct2*,
int, double) )
{ pt2Object = _pt2Object; fpt = tfpt; };

// override function "call" in base class
// no arg list
virtual void Call()
{ (*pt2Object.*fpt) (); };

// For Multi Args
virtual void Call_m(struct1* bkgnd, struct2* geo, int val1,
double val2)
{ (*pt2Object.*fpt) (bkgnd, geo, val1, val2); };


private:

// For No Arguments
void (TClass::*fpt) ();

// For Multi Args
void (TClass::*fpt) (struct1*, struct2*, int, double);

TClass* pt2Object;
};
#endif



In Source Code (MyCode.cpp):

Land objLand;

TSpecificFunctor<Land> specFuncLand_0(&objLand, &Land::init_test);
TSpecificFunctor<Land> specFuncLand_1(&objLand, &LandS::init_test3);

ScatFunctor *funcTable[] = { &specFuncLand_0, &specFuncLand_1 };

// call test function (no arguments)
funcTable[0]->Call();

// call registered multi args function
funcTable[1]->Call_m(str1, str2, Val1, Val2);


When I compile and just use one of the constructors (e.g. the multi
argument case), all works well. However, when I add the no argument
case, I get the following compilation errors:

Errors during compilation:

TstFunctor.h:78: error: declaration of `void
(TClass::*TSpecificFunctor<TClass>::fpt)()'
TstFunctor.h:68: error: conflicts with previous declaration `void
(TClass::*TSpecificFunctor<TClass>::fpt)(struct1*, struct2*, int,
double)'
TstFunctor.h: In constructor
`TSpecificFunctor<TClass>::TSpecificFunctor(TClass*, void (TClass::*)
()) [with TClass = Land]':
MyCode.cpp:258: instantiated from here
TstFunctor.h:42: error: cannot convert `void (Land::*)()' to `void
(Land::*)(struct1*, struct2*, int, double)' in assignment
TstFunctor.h: In member function `void
TSpecificFunctor<TClass>::Call() [with TClass = Land]':
MyCode.cpp:2287: instantiated from here
TstFunctor.h:63: error: too few arguments to function
make[1]: *** [Mycode.o] Error 1


Is there a way to setup my classes to handle various argument lengths
for the functions I need to use (e.g. init_test, init_test3)? I
thought I could over-ride the constructors in TstFunctor.h, but either
I can't, or I'm not doing it correctly.

Thanks for any help / tips that can be provided.

Danny
 

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