I want to pass begin and end iterators to a method. I must not understand
them correctly. In the example below the DoString signature compiles, but
the operations on the passed parameters are not defined.
Thanks,
Chris
#include <iterator>
#include <string>
#include <list>
#include <vector>
using namespace std;
void Tester::DoStrings(iterator<forward_iterator_tag, string> begin,
iterator<forward_iterator_tag, string> end)
{
*begin; // undefined operation
++begin; // undefined operation
}
...
{
list<string> myList;
DoStrings(myList.begin(), myList.end());
vector<string> myVector;
DoString(myVector.begin(), myVector.end());
} 4 1698
Chris Slominski wrote: I want to pass begin and end iterators to a method. I must not understand them correctly. In the example below the DoString signature compiles, but the operations on the passed parameters are not defined.
Thanks, Chris
#include <iterator> #include <string> #include <list> #include <vector> using namespace std;
void Tester::DoStrings(iterator<forward_iterator_tag, string> begin, iterator<forward_iterator_tag, string> end) { *begin; // undefined operation ++begin; // undefined operation }
...
{ list<string> myList; DoStrings(myList.begin(), myList.end());
vector<string> myVector; DoString(myVector.begin(), myVector.end()); }
try:
template <typename ForwardIterator>
void Tester::DoStrings(ForwardIterator begin, ForwardIterator end)
{
*begin;
++begin;
}
Chris Slominski wrote: I must not understand them correctly.
I'd consider this to be a gross understatement...
void Tester::DoStrings(iterator<forward_iterator_tag, string> begin, iterator<forward_iterator_tag, string> end)
There is no such thing like an iterator base class, at least none
which has any functionality. 'std::iterator<>' essentially just adds
necessary declaration of associated types (e.g. the value type, an
iterator category, etc.) but has no functionality on its own. You
probably want to accept arbitrary forward iterators whose value type
is 'std::string'. The easiest approach to do so is to declare your
function like this:
template <typename ForwardIt>
void Test::DoStrings(ForwardIt begin, ForwardIt end) { *begin; // undefined operation ++begin; // undefined operation }
--
<mailto:di***********@yahoo.com> <http://www.dietmar-kuehl.de/>
<http://www.contendix.com> - Software Development & Consulting
"red floyd" <no*****@here.dude> wrote in message
news:WE*****************@newssvr13.news.prodigy.co m... Chris Slominski wrote: I want to pass begin and end iterators to a method. I must not
understand them correctly. In the example below the DoString signature compiles,
but the operations on the passed parameters are not defined.
Thanks, Chris
#include <iterator> #include <string> #include <list> #include <vector> using namespace std;
void Tester::DoStrings(iterator<forward_iterator_tag, string> begin, iterator<forward_iterator_tag, string> end) { *begin; // undefined operation ++begin; // undefined operation }
...
{ list<string> myList; DoStrings(myList.begin(), myList.end());
vector<string> myVector; DoString(myVector.begin(), myVector.end()); }
try:
template <typename ForwardIterator> void Tester::DoStrings(ForwardIterator begin, ForwardIterator end) { *begin; ++begin; }
Thanks for the help and I will likely use the general solution you offer.
Just out of curiosity though, vector<string>::iterator,
list<string>::iterator, set<string>::iterator are all typedef 'ed as some
concrete type. Are the three concrete types related by some common ancestor
that supports the auto-increment and dereference operator?
Chris
On 2005-02-24 12:51:55 -0500, "Chris Slominski" <cj*@jlab.org> said: "red floyd" <no*****@here.dude> wrote in message news:WE*****************@newssvr13.news.prodigy.co m... template <typename ForwardIterator> void Tester::DoStrings(ForwardIterator begin, ForwardIterator end) { *begin; ++begin; }
Thanks for the help and I will likely use the general solution you offer. Just out of curiosity though, vector<string>::iterator, list<string>::iterator, set<string>::iterator are all typedef 'ed as some concrete type. Are the three concrete types related by some common ancestor that supports the auto-increment and dereference operator?
No. I suppose that they could be, on some particular platform, but you
would gain little in doing so, as standard-compliant code could never
make any use of that knowledge anyway.
--
Clark S. Cox, III cl*******@gmail.com This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
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(*)...
|
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...
|
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...
|
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...
|
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...
|
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 = ...
|
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...
|
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
|
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.
|
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);
|
by: Charles Arthur |
last post by:
How do i turn on java script on a villaon, callus and itel keypad mobile phone
|
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
|
by: BarryA |
last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
|
by: nemocccc |
last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
|
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...
|
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...
|
by: marktang |
last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However,...
|
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...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
| |