473,386 Members | 1,712 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,386 software developers and data experts.

iterators

Hi,

I have a general question about iterators

suppose I have a class

class MyClass
{
public:
....
private:
PtrList m_ptrlist<somerecordtype>;
}

PtrList<T> is a class taht has an iterator implemented .. so i could
do:
m_ptrlist::iterator it = m_ptrlist.begin() .. and iterate / modify
items etc.

but suppose i want MyClass to be able to iterate over this list and
present that iteration interface to the user . what is the correct
way to do this?

Thanks!!
Jul 19 '05 #1
1 2740
"Talha" <ta*********@hotmail.com> wrote...
Hi,

I have a general question about iterators

suppose I have a class

class MyClass
{
public:
....
private:
PtrList m_ptrlist<somerecordtype>;
Huh? Didn't you mean

PtrList<somerecordtype> m_ptrlist;

???
} ;
PtrList<T> is a class taht has an iterator implemented .. so i could
do:
m_ptrlist::iterator it = m_ptrlist.begin() .. and iterate / modify
items etc.
No, you couldn't. 'm_ptrlist' is not a type nor is it a namespace.
You have to do

PtrList<somerecordtype>::iterator it = ...
but suppose i want MyClass to be able to iterate over this list and
present that iteration interface to the user . what is the correct
way to do this?


There probably more than one correct way. You could define your own
type (MyClass::iterator, for example) by typedef'ing the PtrList's
one:

class MyClass {
...
typedef PtrList<somerecordtype>::iterator iterator;
};

and then provide your own 'begin', and 'end' member functions that
would return the right iterators:

class MyClass {
...
iterator begin() { return m_ptrlist.begin(); }
iterator end() { return m_ptrlist.end(); }
};

That ought to do it...

Victor
Jul 19 '05 #2

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

10
by: Steven Bethard | last post by:
So, as I understand it, in Python 3000, zip will basically be replaced with izip, meaning that instead of returning a list, it will return an iterator. This is great for situations like: zip(*)...
18
by: deancoo | last post by:
I have gotten into the habit of often using copy along with an insert iterator. There are scenarios where I process quite a lot of data this way. Can someone give me a general feel as to how much...
1
by: Marcin Kaliciñski | last post by:
template<class RanAccIt> void some_algorithm(RanAccIt begin, RanAccIt end) { // this algorithm involves calling std::lexicographical_compare // on range [begin, end), and on reverse of this range...
3
by: codefixer | last post by:
Hello, I am trying to understand if ITERATORS are tied to CONTAINERS. I know the difference between 5 different or 6(Trivial, on SGI). But what I fail to understand is how can I declare all 5...
8
by: babak | last post by:
Hi everyone I have a problem with Iterators and containers in STL that hopefully someone can help me with. This is what I try to do: I have an associative (map) container and I have a...
24
by: Lasse Vågsæther Karlsen | last post by:
I need to merge several sources of values into one stream of values. All of the sources are sorted already and I need to retrieve the values from them all in sorted order. In other words: s1 = ...
14
by: Jiri Kripac | last post by:
Languages such as Simula 67 contain a general concept of coroutines that allow the execution of a method to be suspended without rolling back the stack and then later resumed at the same place as...
2
by: ma740988 | last post by:
typedef std::vector < std::complex < double > > complex_vec_type; // option1 int main() { complex_vec_type cc ( 24000 ); complex_vec_type dd ( &cc, &cc ); } versus
90
by: John Salerno | last post by:
I'm a little confused. Why doesn't s evaluate to True in the first part, but it does in the second? Is the first statement something different? False print 'hi' hi Thanks.
18
by: desktop | last post by:
1) I have this code: std::list<intmylist; mylist.push_back(1); mylist.push_back(2); mylist.push_back(3); mylist.push_back(4);
0
by: taylorcarr | last post by:
A Canon printer is a smart device known for being advanced, efficient, and reliable. It is designed for home, office, and hybrid workspace use and can also be used for a variety of purposes. However,...
0
by: aa123db | last post by:
Variable and constants Use var or let for variables and const fror constants. Var foo ='bar'; Let foo ='bar';const baz ='bar'; Functions function $name$ ($parameters$) { } ...
0
by: ryjfgjl | last post by:
If we have dozens or hundreds of excel to import into the database, if we use the excel import function provided by database editors such as navicat, it will be extremely tedious and time-consuming...
0
by: ryjfgjl | last post by:
In our work, we often receive Excel tables with data in the same format. If we want to analyze these data, it can be difficult to analyze them because the data is spread across multiple Excel files...
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
by: Hystou | last post by:
There are some requirements for setting up RAID: 1. The motherboard and BIOS support RAID configuration. 2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
0
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
0
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.