Reference to pinter

[Fab]

Dear all

I was browsing the OpenFOAM sources a little and I stumbled over types
of the form

T * Tp ( 0 );
T *& Tpr( Tp );

In what particular situation would something like this be useful? I can
only think of that the reference must be initialized?

I am thankful for any feedback!

Thanks
Fab

 

[Jorgen Grahn]

Dear all

I was browsing the OpenFOAM sources a little and I stumbled over types
of the form

T * Tp ( 0 );
T *& Tpr( Tp );

In what particular situation would something like this be useful?

In the situation that applies in OpenFOAM, maybe? What does the rest
of the code tell you?

That said, it seems to me this just creates another (badly chosen)
name "Tpr" for Tp. I fail to see the usefulness of that, but perhaps
I'm missing something.

Sometimes I create references for readability or constness reasons, e.g.

map<int, string>::iterator it = foo();
const string& name = it->second;
// use name instead of it->second

/Jorgen

 

[gwowen]

In what particular situation would something like this be useful?

Maybe in Old Times, after a Tea Party, or A Night Out. Or perhaps by
The Caretaker, The Lover, The Dumb Waiter or any time you fell A
Slight Ache for an adaption of A Remembrance Of Things Past.

 

[Marcel Müller]

I was browsing the OpenFOAM sources a little and I stumbled over types
of the form

T * Tp ( 0 );
T *& Tpr( Tp );

In what particular situation would something like this be useful? I can
only think of that the reference must be initialized?

I am using this from time to time.

Example 1:
// Array of pointers to T, that owns it's elements.
template <class T>
class my_vector<T>
{
...
// Add initial (NULL) element
T*& append();
};

class my_element
{ ...
};

my_vector<my_element> array;
array.append() = new my_element();


Example 2:

class my_queue
{
entry* Head;
...
void insert(entry* elem, entry* after)
{ entry*& qp = after ? after->Next : Head;
entry->Next = qp;
qp = elem;
}
}


Marcel