templates / overloading operator()

[Malcolm Smith]

I have this functor:

struct DeleteIterObjec t
{
template< typename T >
void operator()(cons t T* ptr) const
{
delete ptr;
ptr = NULL;
}
};

Currently, the code is used like this:

FOwnerPolicy.De leteObjects(FCo ntainer.begin() , FContainer.end( ));

where FOwnerPolicy is a policy class of type 'TOwnIteratorOb jectsPolicy',
shown below:

struct TOwnIteratorObj ectsPolicy
{
template< class IterType >
void DeleteObjects(I terType IterB, IterType IterE)
{
std::for_each(I terB, IterE, DeleteIterObjec t());
}
};

Now I'm trying to work out how to specialize DeleteIterObjec t for the case
when 'T' is a std::pair< U*, V* >. I've created another functor that will
bind to either the first or the second element and delete the object - like
this for example:

struct TOwnPairSecondO bjectsPolicy
{
template< class IterType >
void DeleteObjects(I terType IterB, IterType IterE)
{
std::for_each(I terB, IterE, BindPairSecond( DeleteIterObjec t()));
}
};

[ BindPairSecond is similar in design to Bind2nd, where I pass the .second
element to DeleteIterObjec t for processing ]

But I cannot work out how to create a specialized case of
DeleteIterObjec ts(). I would ideally like to convert this:

std::for_each(I terB, IterE, BindPairFirst(D eleteIterObject ()));
std::for_each(I terB, IterE, BindPairSecond( DeleteIterObjec t()));

into a single call such as:

std::for_each(I terB, IterE, DeleteIterObjec t());

I'm sure it can be done by overloading the operator() method of
'DeleteIterObje ct' but I cannot work out the syntax.

Is what I'm after possible ?

--
---
Malcolm Smith
MJ Freelancing
http://www.mjfreelancing.com
Borland Technology Partner

[Paul]

"Malcolm Smith" <mj***********@ optusnet.com.au > wrote in message news:<41******* *************** *@news.optusnet .com.au>...

I have this functor:

struct DeleteIterObjec t
{
template< typename T >
void operator()(cons t T* ptr) const
{
delete ptr;
ptr = NULL;
}
};
Currently, the code is used like this:

FOwnerPolicy.De leteObjects(FCo ntainer.begin() , FContainer.end( ));

where FOwnerPolicy is a policy class of type 'TOwnIteratorOb jectsPolicy',
shown below:

struct TOwnIteratorObj ectsPolicy
{
template< class IterType >
void DeleteObjects(I terType IterB, IterType IterE)
{
std::for_each(I terB, IterE, DeleteIterObjec t());
}
};

Now I'm trying to work out how to specialize DeleteIterObjec t for the case
when 'T' is a std::pair< U*, V* >. I've created another functor that will
bind to either the first or the second element and delete the object - like
this for example:

struct TOwnPairSecondO bjectsPolicy
{
template< class IterType >
void DeleteObjects(I terType IterB, IterType IterE)
{
std::for_each(I terB, IterE, BindPairSecond( DeleteIterObjec t()));
}
};

[ BindPairSecond is similar in design to Bind2nd, where I pass the .second
element to DeleteIterObjec t for processing ]

But I cannot work out how to create a specialized case of
DeleteIterObjec ts(). I would ideally like to convert this:

std::for_each(I terB, IterE, BindPairFirst(D eleteIterObject ()));
std::for_each(I terB, IterE, BindPairSecond( DeleteIterObjec t()));

into a single call such as:

std::for_each(I terB, IterE, DeleteIterObjec t());

I'm sure it can be done by overloading the operator() method of
'DeleteIterObje ct' but I cannot work out the syntax.

Is what I'm after possible ?

Is this any help?

struct DeleteIterObjec t
{
template<typena me T>
void operator()(cons t T)const{std::co ut<<"normal()\n ";}

template<typena me T1,typename T2>
void operator()(cons t std::pair<T1,T2 >)const{std::co ut<<"specialize d\n";}
};

Paul.

[Malcolm Smith]

My first attempt was similar. I'll keep playing.

--
---
Malcolm Smith
MJ Freelancing
http://www.mjfreelancing.com
Borland Technology Partner

Is this any help?

struct DeleteIterObjec t
{
template<typena me T>
void operator()(cons t T)const{std::co ut<<"normal()\n ";}

template<typena me T1,typename T2>
void operator()(cons t std::pair<T1,T2 >)const{std::co ut<<"specialize d\n";} };

Paul.