Accept either an iterator or a reverse_iterator

[Boogie El Aceitoso]

Hi,
I'm writng a function that works an a std::string and should accept either an
iterator or a reverse_iterator. How can I do this? O:-)

[lallous]

"Boogie El Aceitoso" <fr****@telefonica.net> wrote in message
news:pj********************************@4ax.com...

Hi,
I'm writng a function that works an a std::string and should accept either an iterator or a reverse_iterator. How can I do this? O:-)

Function parameter overloading?

Regards,
Elias

[Martijn Lievaart]

On Wed, 03 Dec 2003 16:17:52 +0100, Boogie El Aceitoso wrote:

Hi,
I'm writng a function that works an a std::string and should accept either an
iterator or a reverse_iterator. How can I do this? O:-)

The way this is done most often, is to use a template:

template<typename T1, typename T2>
void print(T1 start, T2 end)
{
while (start != end)
cout << *start++;
}

HTH,
M4

[Josh Sebastian]

On Wed, 03 Dec 2003 16:52:10 +0100, Martijn Lievaart wrote:

On Wed, 03 Dec 2003 16:17:52 +0100, Boogie El Aceitoso wrote:

Hi,
I'm writng a function that works an a std::string and should accept either an
iterator or a reverse_iterator. How can I do this? O:-)
The way this is done most often, is to use a template:

template<typename T1, typename T2>
void print(T1 start, T2 end)

Shouldn't the iterators be the same type?

template<typename Iter>
void print(Iter start, Iter end)
{
while (start != end)
cout << *start++;
}

HTH,
M4

Josh

[Martijn Lievaart]

On Wed, 03 Dec 2003 17:27:29 -0500, Josh Sebastian wrote:

Shouldn't the iterators be the same type?

template<typename Iter>
void print(Iter start, Iter end)

{
while (start != end)
cout << *start++;
}

No, this precludes the use of a const_iterator for one and a normal
iterator for the other. For most cases it will work though.

M4

[Josh Sebastian]

On Thu, 04 Dec 2003 09:25:37 +0100, Martijn Lievaart wrote:

On Wed, 03 Dec 2003 17:27:29 -0500, Josh Sebastian wrote:

Shouldn't the iterators be the same type?

template<typename Iter>
void print(Iter start, Iter end)

{
while (start != end)
cout << *start++;
}

No, this precludes the use of a const_iterator for one and a normal
iterator for the other.

Maybe I'm just lacking in imagination, but that doesn't seem terribly
useful to me. In theory, the two iterators should point to elements of the
same sequence. I don't really see why you'd have a const- and
non-const-iterator to the same sequence.
For most cases it will work though.

I'd hope so, as that's how the standard library functions do it. :-}

Josh

[Martijn Lievaart]

On Thu, 04 Dec 2003 17:47:21 -0500, Josh Sebastian wrote:

On Thu, 04 Dec 2003 09:25:37 +0100, Martijn Lievaart wrote:

On Wed, 03 Dec 2003 17:27:29 -0500, Josh Sebastian wrote:

Shouldn't the iterators be the same type?

No, this precludes the use of a const_iterator for one and a normal
iterator for the other.

Maybe I'm just lacking in imagination, but that doesn't seem terribly
useful to me. In theory, the two iterators should point to elements of the
same sequence. I don't really see why you'd have a const- and
non-const-iterator to the same sequence.

For most cases it will work though.

I'd hope so, as that's how the standard library functions do it. :-}

Hmm, I did it that way, because I remembered that the STL does it my way.
I was wrong. It is only relevant when the iterators really differ, like
input/output iterators.

Thanks for the correction.

M4