Function returning "stream" ?

[StephQ]

At the moment I have a void member function (of a given class) that
takes as input an obj of class type ofstream and write some debug
information to it using the << operator.
I would like to modify the code so that the function returns a
"stream" that can be "sent" to cout or to a file using <<, as this
would give me more flexibility.
I used " " because I'm not sure I'm not using the correct terms
here. :P
Is there an easy way to accomplish this task?
Thank you in advance!

Cheers
Stefano

[Kai-Uwe Bux]

StephQ wrote:

At the moment I have a void member function (of a given class) that
takes as input an obj of class type ofstream and write some debug
information to it using the << operator.
I would like to modify the code so that the function returns a
"stream" that can be "sent" to cout or to a file using <<, as this
would give me more flexibility.
I used " " because I'm not sure I'm not using the correct terms
here. :P

What about returning a std::string? You could send that to cout or a file
using <<. So it seems to fit the description.

Alternatively, you could also make your function use an ostream & instead of
a ofstream &.
Best

Kai-Uwe Bux

[StephQ]

On Mar 6, 1:39 pm, Kai-Uwe Bux <[e-mail]:

StephQ wrote:

At the moment I have a void member function (of a given class) that
takes as input an obj of class type ofstream and write some debug
information to it using the << operator.
I would like to modify the code so that the function returns a
"stream" that can be "sent" to cout or to a file using <<, as this
would give me more flexibility.
I used " " because I'm not sure I'm not using the correct terms
here. :P

What about returning a std::string? You could send that to cout or a file
using <<. So it seems to fit the description.

Alternatively, you could also make your function use an ostream & instead of
a ofstream &.

Best

Kai-Uwe Bux

See my reply above.
I have never used ostream before. Do you have a link to a reference /
tutorial about it and streams in general?

Best
StephQ

[Kai-Uwe Bux]

StephQ wrote:

On Mar 6, 1:39 pm, Kai-Uwe Bux <[e-mail]:

>StephQ wrote:

At the moment I have a void member function (of a given class) that
takes as input an obj of class type ofstream and write some debug
information to it using the << operator.
I would like to modify the code so that the function returns a
"stream" that can be "sent" to cout or to a file using <<, as this
would give me more flexibility.
I used " " because I'm not sure I'm not using the correct terms
here. :P

What about returning a std::string? You could send that to cout or a file
using <<. So it seems to fit the description.

Alternatively, you could also make your function use an ostream & instead
of a ofstream &.

Best

Kai-Uwe Bux

See my reply above.

See my reply to that reply.

I have never used ostream before. Do you have a link to a reference /
tutorial about it and streams in general?

Unfortunately, computer books are incredibly booring to me (with very,
_very_ few exceptions). I don't read them unless I have to look up
something. For that, I usually refer to the C++ standard. However, it
appears to be general consensus in this forum that this is not a good
recommendation.

However, for the case you mentioned, I take it that you have some function

void log ( std::ofstream & the_stream ) {
...
}

I would try to just changing it to

void log ( std::ostream & the_stream ) {
// same body
}

Unless you use file-specific methods (for which I don't see a need), you
should get away with that small change.
Best

Kai-Uwe Bux

[Jim Langston]

"Kai-Uwe Bux" <jk********@gmx.netwrote in message
news:es********@murdoch.acc.Virginia.EDU...

StephQ wrote:

>On Mar 6, 1:39 pm, Kai-Uwe Bux <[e-mail]:

>>StephQ wrote:
At the moment I have a void member function (of a given class) that
takes as input an obj of class type ofstream and write some debug
information to it using the << operator.
I would like to modify the code so that the function returns a
"stream" that can be "sent" to cout or to a file using <<, as this
would give me more flexibility.
I used " " because I'm not sure I'm not using the correct terms
here. :P

What about returning a std::string? You could send that to cout or a
file
using <<. So it seems to fit the description.

Alternatively, you could also make your function use an ostream &
instead
of a ofstream &.

Best

Kai-Uwe Bux

See my reply above.

See my reply to that reply.

>I have never used ostream before. Do you have a link to a reference /
tutorial about it and streams in general?

Unfortunately, computer books are incredibly booring to me (with very,
_very_ few exceptions). I don't read them unless I have to look up
something. For that, I usually refer to the C++ standard. However, it
appears to be general consensus in this forum that this is not a good
recommendation.

However, for the case you mentioned, I take it that you have some function

void log ( std::ofstream & the_stream ) {
...
}

I would try to just changing it to

void log ( std::ostream & the_stream ) {
// same body
}

Unless you use file-specific methods (for which I don't see a need), you
should get away with that small change.

Umm.. I don't see a change. I think you meant to change it to:

std::ostream& log ( std::ostream& the_stream ) {
// same body
return the_stream;
}

didnt' you?

>

Best

Kai-Uwe Bux

[Kai-Uwe Bux]

Jim Langston wrote:

>
"Kai-Uwe Bux" <jk********@gmx.netwrote in message
news:es********@murdoch.acc.Virginia.EDU...

>StephQ wrote:

>>On Mar 6, 1:39 pm, Kai-Uwe Bux <[e-mail]:
StephQ wrote:
At the moment I have a void member function (of a given class) that
takes as input an obj of class type ofstream and write some debug
information to it using the << operator.
I would like to modify the code so that the function returns a
"stream" that can be "sent" to cout or to a file using <<, as this
would give me more flexibility.
I used " " because I'm not sure I'm not using the correct terms
here. :P

What about returning a std::string? You could send that to cout or a
file
using <<. So it seems to fit the description.

Alternatively, you could also make your function use an ostream &
instead
of a ofstream &.

Best

Kai-Uwe Bux

See my reply above.

See my reply to that reply.

>>I have never used ostream before. Do you have a link to a reference /
tutorial about it and streams in general?

Unfortunately, computer books are incredibly booring to me (with very,
_very_ few exceptions). I don't read them unless I have to look up
something. For that, I usually refer to the C++ standard. However, it
appears to be general consensus in this forum that this is not a good
recommendation.

However, for the case you mentioned, I take it that you have some
function

void log ( std::ofstream & the_stream ) {
...
}

I would try to just changing it to

void log ( std::ostream & the_stream ) {
// same body
}

Unless you use file-specific methods (for which I don't see a need), you
should get away with that small change.

Umm.. I don't see a change. I think you meant to change it to:

std::ostream& log ( std::ostream& the_stream ) {
// same body
return the_stream;
}

didnt' you?

No, I did not. Rereading what I wrote, I find that I changed exactly what I
meant to change. You just missed it. Hint: I removed just one letter!
Best

Kai-Uwe Bux