Search Results

Search found 173 results on 7 pages for 'iterators'.

Page 4/7 | < Previous Page | 1 2 3 4 5 6 7  | Next Page >

• C++ Iterator lifetime and detecting invalidation

  - by DK.

  Based on what's considered idiomatic in C++11: should an iterator into a custom container survive the container itself being destroyed? should it be possible to detect when an iterator becomes invalidated? are the above conditional on "debug builds" in practice? Details: I've recently been brushing up on my C++ and learning my way around C++11.…

  Read the article

• We've completed the first iteration

  - by CliveT

  There are a lot of features in C# that are implemented by the compiler and not by the underlying platform. One such feature is a lambda expression. Since local variables cannot be accessed once the current method activation finishes, the compiler has to go out of its way to generate a new class which acts as a home for any variable whose…

  Read the article

• Is there a writable iterator in Java?

  - by Lukasz Lew

  In C+ one can use iterators for writing to a sequence. Simplest example would be: vector<int> v; for (vector<int>::iterator it = v.begin(); it!=v.end(); ++it) { *it = 42; } I need something more complicated - keep iterator as a class member for a later use. But I don't know how to get this behavior from Java iterators. Are…

  Read the article

• Function template accepting nothing less than a bidirectional iterator or a pointer

  - by san

  I need a function template that accepts two iterators that could be pointers. If the two arguments are random_access iterators I want the return type to be an object of std::iterator<random_access_iterator_tag, ...> type else a std::iterator<bidirectional_iterator_tag, ...> type. I also want the code to refuse compilation…

  Read the article

• In which versions of ruby are external iterator speeds improved?

  - by Andrew Grimm

  According to this rubyquiz, external iterators used to be slow, but are now faster. Is this an improvement only available in YARV (the C-based implementation of ruby 1.9), or is this also available in the C-based implementation of ruby 1.8.7? Also, does enum_for rely on external iterators?

  Read the article

• Substitute for Iterator that is Serialization

  - by Mahmoud

  I'm working on a GWT project, and I have a bunch of Java classes that use Java Object Iterators on the server side. As I was reading through the internet...Iterators seem to not be serializable preventing me from sending them over to the client side from the server side. My question is is there an efficient way to serialize the iterator or…

  Read the article

• How to load/save C++ class instance (using STL containers) to disk

  - by supert

  I have a C++ class representing a hierarchically organised data tree which is very large (~Gb, basically as large as I can get away with in memory). It uses an STL list to store information at each node plus iterators to other nodes. Each node has only one parent, but 0-10 children. Abstracted, it looks something like: struct node {…

  Read the article

• Pointers into elements in a container

  - by Pillsy

  Say I have an object: struct Foo { int bar_; Foo(int bar) bar_(bar) {} }; and I have an STL container that contains Foos, perhaps a vector, and I take // Elsewhere... vector<Foo> vec; vec.push_back(Foo(4)); int *p = &(vec[0].bar_) This is a terrible idea, right? The reason is that vector is going to be…

  Read the article

• Why can't I sort this container?

  - by Knowing me knowing you

  Please don't mind that there is no insert fnc and that data are hardcoded. The main purpouse of it is to correctly implement iterator for this container. //file Set.h #pragma once template<class T> class Set { template<class T> friend ostream& operator<<(ostream& out, const Set<T>& obj);…

  Read the article

• Iterator for boost::variant

  - by Ivan

  Hy there, I'm trying to adapt an existing code to boost::variant. The idea is to use boost::variant for a heterogeneous vector. The problem is that the rest of the code use iterators to access the elements of the vector. Is there a way to use the boost::variant with iterators? I've tried typedef boost::variant<Foo, Bar>…

  Read the article

• Is it a good idea to create an STL iterator which is noncopyable?

  - by BillyONeal

  Most of the time, STL iterators are CopyConstructable, because several STL algorithms require this to improve performance, such as std::sort. However, I've been working on a pet project to wrap the FindXFile API (previously asked about), but the problem is it's impossible to implement a copyable iterator around this API. A find…

  Read the article

• Java: Is there a way to efficiently insert or remove many elements from the middle of a LinkedList?

  - by allyourcode

  I was expecting to find this in Java's LinkedList, since the point of linked lists is to be able to efficiently insert (and remove) anywhere (assuming you have some kind of pointer to the location where you want to insert or remove). I'm not finding anything in the API though. Am I overlooking something? The closest thing I can…

  Read the article

• An iterator is a section of code that returns an ordered sequence of values of the same type.

  Among other languages, iterators are used in C++, C# and other .NET languages, Java, Ruby, and Python. The primary purpose of an iterator is to allow a user to process every element of a container while isolating the user from the internal structure of the container.  read moreBy Peter BrombergDid you know that…

  Read the article

• How might I wrap the FindXFile-style APIs to the STL-style Iterator Pattern in C++?

  - by BillyONeal

  Hello everyone :) I'm working on wrapping up the ugly innards of the FindFirstFile/FindNextFile loop (though my question applies to other similar APIs, such as RegEnumKeyEx or RegEnumValue, etc.) inside iterators that work in a manner similar to the Standard Template Library's istream_iterators. I have two problems…

  Read the article

• using yield in C# like I would in Ruby

  - by Sarah Vessels

  Besides just using yield for iterators in Ruby, I also use it to pass control briefly back to the caller before resuming control in the called method. What I want to do in C# is similar. In a test class, I want to get a connection instance, create another variable instance that uses that connection, then pass the…

  Read the article

• Writing my own implementation of stl-like Iterator in C++.

  - by Negai

  Good evening everybody, I'm currently trying to understand the intrinsics of iterators in various languages i.e. the way they are implemented. For example, there is the following class exposing the list interface. template<class T> class List { public: virtual void Insert( int beforeIndex, const…

  Read the article

• Find vertices of a convex hull

  - by Jeff Bullard

  I am attempting to do this within CGAL. From a 3D point cloud, find the convex hull, then loop over the finite facets of the convex hull and print each facet's vertices. It seems like there should be a straightforward way to do this; I would have expected that 3D polyhedra would own a vector of facet objects,…

  Read the article

• Optimistic work sharing on sparsely distributed systems

  - by Asti

  What would a system like BOINC look like if it were written today? At the time BOINC was written, databases were the primary choice for maintaining a shared state and concurrency among nodes. Since then, many approaches have been developed for tasking with optimistic concurrency (OT, partial synchronization…

  Read the article

• New DMV–yes… no… that’s complicated

  - by Michael Zilberstein

  Remember the excitement about new sys.dm_exec_query_profiles DMV? It promised to be a gamechanger, providing query visibility at a runtime and easily extractable information about heavy iterators in execution plan. So it has been announced but missing. Now in CTP2 it is finally here. So, singing one of my…

  Read the article

• Frustrations about which language to use [closed]

  - by Joshua

  I am way too indecisive. I have an idea for a (admittedly craptastic) GUI program, so I start writing it in C# .NET WinForms. Then like halfway through I'm like, damn I should have written this in Qt. So I start writing it in Qt and remember why I hate C++ STL iterators so much. So in my head I go …

  Read the article

• fail-fast iterator

  - by joy

  I get this definition : As name suggest fail-fast Iterators fail as soon as they realized that structure of Collection has been changed since iteration has begun. what it mean by since iteration has begun? is that mean after Iterator it=set.iterator() this line of code? public static void…

  Read the article

• Pass first element of jsp list to javascript

  - by Lucian Enache

  Ok so I'm trying to access the first element of a JSP list, here's what I've come up with so far without any kind of luck: onclick="alert('<%=list[0]%>');" What's the best approach to access the first element and eventually to pass it to a javascript variable/function ? I've heard…

  Read the article

• Design pattern for adding / removing elements

  - by de3

  Wikipedia's definition for Iterator pattern design: the Iterator pattern is a design pattern in which iterators are used to access the elements of an aggregate object sequentially without exposing its underlying implementation. Iterator interface in java provides the following methods …

  Read the article

• Can 'iterator' type just subclass 'const_iterator'?

  - by doublep

  After another question about iterators I'm having some doubts about custom containers. In my container, iterator is a subclass of const_iterator, so that I get conversion from non-const to const "for free". But is this allowed or are there any drawbacks or non-working scenarios for…

  Read the article

• Boost multi_index ordered_unique Median Value

  - by Autopulated

  I would like to quickly retrieve the median value from a boost multi_index container with an ordered_unique index, however the index iterators aren't random access (I don't understand why they can't be, though this is consistent with std::set...). Is there a faster/neater way to do…

  Read the article

< Previous Page | 1 2 3 4 5 6 7  | Next Page >