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  • Some clarification on rvalue references

    - by Dennis Zickefoose
    First: where are std::move and std::forward defined? I know what they do, but I can't find proof that any standard header is required to include them. In gcc44 sometimes std::move is available, and sometimes its not, so a definitive include directive would be useful. When implementing move semantics, the source is presumably left in an undefined state. Should this state necessarily be a valid state for the object? Obviously, you need to be able to call the object's destructor, and be able to assign to it by whatever means the class exposes. But should other operations be valid? I suppose what I'm asking is, if your class guarantees certain invariants, should you strive to enforce those invariants when the user has said they don't care about them anymore? Next: when you don't care about move semantics, are there any limitations that would cause a non-const reference to be preferred over an rvalue reference when dealing with function parameters? void function(T&); over void function(T&&); From a caller's perspective, being able to pass functions temporary values is occasionally useful, so it seems as though one should grant that option whenever it is feasible to do so. And rvalue references are themselves lvalues, so you can't inadvertently call a move-constructor instead of a copy-constructor, or something like that. I don't see a downside, but I'm sure there is one. Which brings me to my final question. You still can not bind temporaries to non-const references. But you can bind them to non-const rvalue references. And you can then pass along that reference as a non-const reference in another function. void function1(int& r) { r++; } void function2(int&& r) { function1(r); } int main() { function1(5); //bad function2(5); //good } Besides the fact that it doesn't do anything, is there anything wrong with that code? My gut says of course not, since changing rvalue references is kind of the whole point to their existence. And if the passed value is legitimately const, the compiler will catch it and yell at you. But by all appearances, this is a runaround of a mechanism that was presumably put in place for a reason, so I'd just like confirmation that I'm not doing anything foolish.

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  • Why do some people prefer "T const&" over "const T&"?

    - by Michael Aaron Safyan
    So, I realize that const T& and T const& are identical and both mean a reference to a const T. In both cases, the reference is also constant (references cannot be reassigned, unlike pointers). I've observed, in my somewhat limited experience, that most C++ programmers use const T&, but I have come across a few people who use T const&. Is this just a personal preference? Why is one chosen over the other?

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  • How to pass objects to functions in C++?

    - by Rakesh K
    I am new to C++ programming, but I have experience in Java. I need guidance on how to pass objects to functions in C++. Do I need to pass pointers, references, or non-pointer and non-reference values? I remember in Java there are no such issues since we pass just the variable that holds reference to the objects. It would be great if you could also explain where to use each of those options.

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  • The endpoint reference (EPR) for the Operation not found is

    - by Denise Wu
    I have been struggling with the following error the last couple of days can you please help! I generated my server and client code using the wsdl2java tool from a wsdl 2.0 file. When invoking the webservice I am getting the following error: org.apache.axis2.AxisFault: The endpoint reference (EPR) for the Operation not found is /axis2/services/MyService/authentication/?username=Denise345&password=xxxxx and the WSA Action = null My service is displayed on the axis2 webpage with all available methods. Here is the output from TcpMon ============== Listen Port: 8090 Target Host: 127.0.0.1 Target Port: 8080 ==== Request ==== GET /axis2/services/MyService/authentication/?username=Denise345&password=xxxxx HTTP/1.1 Content-Type: application/x-www-form-urlencoded; charset=UTF-8 SOAPAction: "" User-Agent: Axis2 Host: 127.0.0.1:8090 ==== Response ==== HTTP/1.1 500 Internal Server Error Server: Apache-Coyote/1.1 Content-Type: application/xml;charset=UTF-8 Transfer-Encoding: chunked Date: Thu, 12 May 2011 15:53:20 GMT Connection: close 12b <soapenv:Reason xmlns:soapenv="http://www.w3.org/2003/05/soap-envelope"> <soapenv:Text xml:lang="en-US">The endpoint reference (EPR) for the Operation not found is /axis2/services/MyService/authentication/?username=Denise345&password=xxxxx and the WSA Action = null</soapenv:Text></soapenv:Reason> 0 ============== I am using: * axis2-1.5.4 * Tomcat 7.0.8 * wsdl 2.0 file Please help!

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  • Null Reference getting REMOTE_ADDR

    - by Josh
    I have an ASMX web service running under IIS7 in classic mode. This service has the following code: try { env.ExternalIP = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"]; } catch (Exception ex) { LogWriter.WriteError(ex); env.ExternalIP="000.000.000.000"; } This results in the following stack trace. I only modified the names of usercode call stack here to protect the innocent: Message: An Exception of type: NullReferenceException occured in method: GetAdditionalServerVar ExceptionMsg: Object reference not set to an instance of an object. ===Stack Trace=== at System.Web.Hosting.ISAPIWorkerRequestInProc.GetAdditionalServerVar(Int32 index) at System.Web.Hosting.ISAPIWorkerRequestInProc.GetServerVariable(String name) at System.Web.HttpRequest.AddServerVariableToCollection(String name) at System.Web.HttpRequest.FillInServerVariablesCollection() at System.Web.HttpServerVarsCollection.Populate() at System.Web.HttpServerVarsCollection.Get(String name) at System.Collections.Specialized.NameValueCollection.get_Item(String name) at MyService.MyMethod() I'm at a loss here as this is very basic plain vanilla code. EDIT This gets even stranger. I have added some basic code just wondering what server variables I can get at this point. This fails with the same exception when I try and get all the keys: System.NullReferenceException: Object reference not set to an instance of an object. at System.Web.Hosting.ISAPIWorkerRequestInProc.GetAdditionalServerVar(Int32 index) at System.Web.Hosting.ISAPIWorkerRequestInProc.GetServerVariable(String name) at System.Web.HttpRequest.AddServerVariableToCollection(String name) at System.Web.HttpRequest.FillInServerVariablesCollection() at System.Web.HttpServerVarsCollection.Populate() at System.Web.HttpServerVarsCollection.get_AllKeys() at MyService.MyHelper() When I was looking at the framework code looks like this could happen when the array which caches the server variables isn't populated and it looks like this occurs when there a null pointer to some Context...which seems like a fairly core piece of the framework code. I suppose it's time to burn up one of our support tickets with Microsoft.

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  • Pass WPF UserControl reference to another UserControl

    - by Rob Bell
    I've created two UserControls, a ValidationManager and a ValidationOutput. On a given form there is one ValidationManager and several ValidationOutput controls, one for each control that is validated. The ValidationManager is given a list of validation errors when the form is submitted, I want each ValidationOutput control to look at this list and see if there are any errors relevant to them. The code looks a bit like this: <r:ValidationManager x:Name="myValidationManager" /> ... <TextBox Name="SomeField" /> <r:ValidationOutput FieldName="SomeField" /> I need to pass a reference to the ValidationManager to each of the ValidationOutput controls. I've added a ValidationManager property to the ValidationOutput UserControl but don't know how to pass the reference to the control. I've tried the following but am just clutching at straws: <r:ValidationOutput ValidationManager="myValidationManager" /> ...and... <r:ValidationOutput ValidationManager="{Binding myValidationManager}" /> The first results in an error "Property 'ValidationManager' was not found or is not serializable for type 'ValidationOutput'" and the second "A 'Binding' cannot be set on the 'ValidationManager' property of type 'ValidationControl'. A 'Binding' can only be set on a DependencyProperty of a DependencyObject."

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  • Problem compiling gnustep-gui-0.16.0 undefined reference to png_sizeof

    - by stefanB
    I'm trying to compile GNUstep on a linux box but gnustep-gui-0.16.0 package is failing. I downloaded GNUstep Startup stable 0.20.1 (http://wwwmain.gnustep.org/resources/downloads.php)and follow instructions about how to compile (./configure && make). I'm getting this error: libgnustep-gui.so: undefined reference to 'png_sizeof' I have compiled latest libpng (1.2.34) and I can see that png_sizeof is defined as macro. However, I'm not quite sure how to fix the gnustep-gui-0.16.0 build. I tried to pass the include/lib directory where libpng is installed to configure build but nothing seems to help. I have quite up to date linux box but using gcc 3.3 (upgrade is not an option - but this should not be a problem). Full error: Making all for tool set_show_service... Compiling file set_show_service.m ... Linking tool set_show_service ... ../Source/./obj/libgnustep-gui.so: undefined reference to `png_sizeof' collect2: ld returned 1 exit status gmake[3]: *** [obj/set_show_service] Error 1 gmake[2]: *** [set_show_service.all.tool.variables] Error 2 gmake[1]: *** [internal-all] Error 2 gmake[1]: Leaving directory `/home/bla/local/src/gnustep-startup-0.22.0/build/gnustep-gui-0.16.0' gmake[3]: *** [obj/set_show_service] Error 1 gmake[2]: *** [set_show_service.all.tool.variables] Error 2 gmake[1]: *** [internal-all] Error 2 Any suggestions? Thanks

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  • WPF - How to properly reference a class from XAML

    - by Andy T
    OK, this is a super super noob question, one that I'm almost embarrassed to ask... I want to reference a class in my XAML file. It's a DataTemplateSelector for selecting the right edit template for a DataGrid column. Anyway, I've written the class into my code behind, added the local namespace to the top of top of the XAML, but when I try to reference the class from the XAML, it tells me the class does not exist in the local namespace. I must be missing something really really simple but I just can't understand it... Here's my code. XAML: <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:tk="http://schemas.microsoft.com/wpf/2008/toolkit" xmlns:local="clr-namespace:CustomFields" xmlns:col="clr-namespace:System.Collections;assembly=mscorlib" xmlns:sys="clr-namespace:System;assembly=mscorlib" x:Class="CustomFields.MainWindow" x:Name="Window" Title="Define Custom Fields" Width="425" Height="400" MinWidth="425" MinHeight="400"> <Window.Resources> <ResourceDictionary> <local:RangeValuesEditTemplateSelector> blah blah blah... </local:RangeValuesEditTemplateSelector> </ResourceDictionary> </Window.Resources> C#: namespace CustomFields { /// /// Interaction logic for MainWindow.xaml /// public partial class MainWindow : Window { public MainWindow() { this.InitializeComponent(); // Insert code required on object creation below this point. } } public class RangeValuesEditTemplateSelector : DataTemplateSelector { public RangeValuesEditTemplateSelector(){ MessageBox.Show("hello"); } } } Any ideas what I'm doing wrong? I thought this should be simple as 1-2-3... Thanks! AT

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  • Simulating pass by reference for an array in Java

    - by Leif Andersen
    I was wondering, in java, is it possible to in anyway, simulate pass by reference for an array? Yes, I know the language doesn't support it, but is there anyway I can do it. Say, for example, I want to create a method that reverses the order of all the elements in an array. (I know that this code snippet isn't the best example, as there is a better algorithms to do this, but this is a good example of the type of thing I want to do for more complex problems). Currently, I need to make a class like this: public static void reverse(Object[] arr) { Object[] tmpArr = new Object[arr.length]; count = arr.length - 1; for(Object i : arr) tmpArr[count--] = i; // I would like to do arr = tmpArr, but that will only make the shallow // reference tmpArr, I would like to actually change the pointer they passed in // Not just the values in the array, so I have to do this: count = arr.length - 1; for(Object i : tmpArr) arr[count--] = i; return; } Yes, I know that I could just swap the values until I get to the middle, and it would be much more efficient, but for other, more complex purposes, is there anyway that I can manipulate the actual pointer? Again, thank you.

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  • python: how to design a container with elements that must reference their container

    - by Luke404
    (the title is admittedly not that great. Please forgive my English, this is the best I could think of) I'm writing a python script that will manage email domains and their accounts, and I'm also a newby at OOP design. My two (related?) issues are: the Domain class must do special work to add and remove accounts, like adding/removing them to the underlying implementation how to manage operations on accounts that must go through their container To solve the former issue I'd add a factory method to the Domain class that'll build an Account instance in that domain, and a 'remove' (anti-factory?) method to handle deletions. For the latter this seems to me "anti-oop" since what would logically be an operation on an Account (eg, change password) must always reference the containing Domain. Seems to me that I must add to the Account a reference back to the Domain and use that to get data (like the domain name) or call methods on the Domain class. Code example (element uses data from the container) that manages an underlying Vpopmail system: class Account: def __init__(self, name, password, domain): self.name = name self.password = password self.domain = domain def set_password(self, password): os.system('vpasswd %s@%s %s' % (self.name, self.domain.name, password) self.password = password class Domain: def __init__(self, domain_name): self.name = domain_name self.accounts = {} def create_account(self, name, password): os.system('vadduser %s@%s %s' % (name, self.name, password)) account = Account(name, password, self) self.accounts[name] = account def delete_account(self, name): os.system('vdeluser %s@%s' % (name, self.name)) del self.accounts[name] another option would be for Account.set_password to call a Domain method that would do the actual work - sounds equally ugly to me. Also note the duplication of data (account name also as dict key), it sounds logical (account names are "primary key" inside a domain) but accounts need to know their own name.

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  • TypeError: Error #1009 - (Null reference error) With Flash.

    - by Wind Chimez
    I am not an expert in flash, but i do work with AS and tweak Flash projects , though not having deep expertise in it. Currently i need to revamp a flash website done by one another guy, and the code base given to me, upon execution is throwing the following error. "--- TypeError: Error #1009: Cannot access a property or method of a null object reference. at NewSite_fla::MainTimeline/__setProp_ContactOutP1_ContactOut_Contents_0() at NewSite_fla::MainTimeline/frame1() --" The structure of the project is like, it has the different sections split into different movie clips. There is no single main timeline, but click actions on different areas of seperate movie clips will take them between one another. All the AS logic of event handling are written inline in FLA , no seperate Document class exists. Preloader Movie clip is the first one getting loaded. As i understood the error is getting thrown initially itself, and it is not happening due to any Action script logic written inline, because it is throwing error even before hitting the first inline AS code. I am not able to figure Out what exactly it causing the problem, or where to resolve it. I setup the stuff online, for reference if anybody want to take a look at it, and here is the link.You need to have flash debugger turned ON in your browser, if need to see the exception getting triggered. http://tinyurl.com/2alvlfx I really got stuck at this point. Any help will be great.I had not seen the particular solution i am looking for anywhere yet, though Error #1009 is common.

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  • Rhino Commons and Rhino Mocks Reference Documents?

    - by Ogre Psalm33
    Ok, is it just me, or does there seem to be a lack of (easy to find) reference documentation for Rhino Commons and Rhino Mocks? My coworkers have started using Rhino Mocks and Rhino Commons (particularly the NHibernate stuff), and I found a few tutorial-ish examples, which were good. But when I see them making use of a class in their code--let's pick something like Rhino.Commons.NHRepository, for example--I have been having a hard time just finding someplace on the web that tells me what Rhino.Commons.NHRepository is or what it does. I like to learn by looking at real examples, but using this approach, it's very handy to look at what the full docs are for a class, instead of just the current context. Similarly, I saw IaMockedRepository.Expect(...) being used in some code, but it took me forever to finally find this page that explains the AAA syntax for Rhino Mocks, which made it clear to me. I've found the Ayende.com wiki on Rhino Commons, but that seems to have a number of broken links. To me, the Rhino libraries seem like a great set of libraries in need of some desperate community help in the documentation area (Of course, as we all know, documentation is not the forte of most coders, and incomplete docs are all too common). Does anyone know if this is something in the works, someplace that some volunteer documenters are needed, or is there some great reference docs out there that I have somehow missed to Rhino Mocks and Rhino Commons?

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  • TypeError: Error #1009 - (Null reference error) With Flash.

    - by Wind Chimez
    I am not an expert in flash, but i do work with AS and tweak Flash projects , though not having deep expertise in it. Currently i need to revamp a flash website done by one another guy, and the code base given to me, upon execution is throwing the following error. "--- TypeError: Error #1009: Cannot access a property or method of a null object reference. at NewSite_fla::MainTimeline/__setProp_ContactOutP1_ContactOut_Contents_0() at NewSite_fla::MainTimeline/frame1() --" The structure of the project is like, it has the different sections split into different movie clips. There is no single main timeline, but click actions on different areas of seperate movie clips will take them between one another. All the AS logic of event handling are written inline in FLA , no seperate Document class exists. Preloader Movie clip is the first one getting loaded. As i understood the error is getting thrown initially itself, and it is not happening due to any Action script logic written inline, because it is throwing error even before hitting the first inline AS code. I am not able to figure Out what exactly it causing the problem, or where to resolve it. I really got stuck at this point. Any help will be great.I had not seen the particular solution i am looking for anywhere yet, though Error #1009 is common. I uploaded the fla, here ( http://tinyurl.com/249e95p ), for reference.It may not be working , since the included/refered video files and all are not there, but reviwing the action code/movie clips will be possible. Please let me know if somebody will be able to trace the issue exactly.

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  • Null reference exceptions in .net

    - by Carlo
    Hello, we're having this big problem with our application. It's a rather large application with several modules, and thousands and thousands lines of code. A lot of parts of the application are designed to exist only with a reference to another object, for example a Person object can never exists without a House object, so if you at any point in the app say: bool check = App.Person.House == null; check should always be false (by design), so, to keep using that example, while creating modules, testing, debugging, App.Person.House is never null, but once we shipped the application to our client, they started getting a bunch of NullReferenceException with the objects that by design, should never have a null reference. They tell us the bug, we try to reproduce it here, but 90% of the times we can't, because here it works fine. The app is being developed with C# and WPF, and by design, it only runs on Windows XP SP 3, and the .net framework v3.5, so we KNOW the user has the same operative system, service pack, and .net framework version as we do here, but they still get this weird NullReferenceExceptions that we can't reproduce. So, I'm just wondering if anyone has seen this before and how you fixed it, we have the app running here at least 8 hours a day in 5 different computers, and we never see those exceptions, this only happens to the client for some reason. ANY thought, any clue, any solution that could get us closer to fixing this problem will be greatly appreciated. Thanks!

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  • Why "Not an ARRAY reference" error?

    - by Sandra Schlichting
    I have this script #!/usr/bin/perl use strict; use warnings; use yy; my $data = [ ["aax", "ert", "ddd"], ["asx", "eer", "kkk"], ["xkk", "fff", "lll"], ["xxj", "vtt", "lle"], ]; use Test::More tests => 4; is(yy::type1_to_type2(\$data, 'aax'), 'ert'); is(yy::type1_to_type3(\$data, 'asx'), 'kkk'); is(yy::type2_to_type3(\$data, 'fff'), 'lll'); is(yy::type3_to_type1(\$data, 'lle'), 'xxj'); which uses this module package yy; sub typeX_to_typeY { my ($x, $y, $data, $str) = @_; foreach (@$data) { if ($_->[$x - 1] eq $str) { return $_->[$y - 1]; } } return; } sub type1_to_type2 { typeX_to_typeY(1, 2, @_) } sub type1_to_type3 { typeX_to_typeY(1, 3, @_) } sub type2_to_type1 { typeX_to_typeY(2, 1, @_) } sub type2_to_type3 { typeX_to_typeY(2, 3, @_) } sub type3_to_type1 { typeX_to_typeY(3, 1, @_) } sub type3_to_type2 { typeX_to_typeY(3, 2, @_) } 1; and gives this error Not an ARRAY reference at yy.pm line 6. # Looks like your test died before it could output anything. The line it complains about is foreach (@$data) { Isn't this the way to pass an array reference? What am I doing wrong?

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  • Google Maps in Drupal: reference to gmap object from JavaScript

    - by user280817
    Is there a way to obtain JavaScript references to the Google maps that are embedded into Drupal pages by the GMap module? I want to be able to manipulate the maps in these pages. I want to pan and zoom them. But I cannot find a reference to an embedded map object. I've dissected the relevant JavaScript objects Drupal.gmap and Drupal.settings.gmap with no success--unless I've overlooked something. The Drupal GMap module doesn't seem to explicitly provide references (within its API) to the GMap objects that it embeds into pages. It just generates themed text which is interpolated into the page. The technique of passing the HTML ID of the map container to either the GMap2 object constructor or the similar Drupal.gmap.getMap() function in order to obtain a map reference doesn't appear to work: Both simply return an instance to a new map, one having the same dimensions and basic characteristics of the original map, but apparently sans all of its overlays (which could contain markers). And I have to call setCenter() on it before I can use it, which initializes the structure, so I know it has no overlays.

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  • Remove pointer object whose reference is mantained in three different lists

    - by brainydexter
    I am not sure how to approach this problem: 'Player' class mantains a list of Bullet* objects: class Player { protected: std::list< Bullet* > m_pBullet_list; } When the player fires a Bullet, it is added to this list. Also, inside the constructor of bullet, a reference of the same object is updated in CollisionMgr, where CollisionMgr also mantains a list of Bullet*. Bullet::Bullet(GameGL*a_pGameGL, Player*a_pPlayer) : GameObject( a_pGameGL ) { m_pPlayer = a_pPlayer; m_pGameGL->GetCollisionMgr()->AddBullet(this); } class CollisionMgr { void AddBullet(Bullet* a_pBullet); protected: std::list< Bullet*> m_BulletPList; } In CollisionMgr.Update(); based on some conditions, I populate class Cell which again contain a list of Bullet*. Finally, certain conditions qualify a Bullet to be deleted. Now, these conditions are tested upon while iterating through a Cell's list. So, if I have to delete the Bullet object, from all these places, how should I do it so that there are no more dangling references to it? std::list< Bullet*>::iterator bullet_it; for( bullet_it = (a_pCell->m_BulletPList).begin(); bullet_it != (a_pCell->m_BulletPList).end(); bullet_it++) { bool l_Bullet_trash = false; Bullet* bullet1 = *bullet_it; // conditions would set this to true if ( l_Bullet_Trash ) // TrashBullet( bullet1 ); continue; } Also, I was reading about list::remove, and it mentions that it calls the destructor of the object we are trying to delete. Given this info, if I delete from one list, the object does not exist, but the list would still contain a reference to it..How do I handle all these problems ? Can someone please help me here ? Thanks PS: If you want me to post more code or provide explanation, please do let me know.

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  • Add webservice reference, the classes in different file

    - by ArunDhaJ
    Hi, When I add webservice as service reference in my .Net project, it creates a service folder within "Service References". All the interfaces and classes are contained within that service folder. I wanted to know how to split the interface's method and classes. Actually I wanted the web service reference to import classes defined in different dll. I wanted to define this way because of my design constraints. I've 3 layered application. Of which third layer is communication layer which holds all web service references. second is business layer and first is presentation layer. If the class declarations are in layer-3 and I'm accessing those classes from presentation layer, it is logically a cross-layer-access-violation. Instead, I wanted a separate project which holds only the class declarations and this would be used in all 3 layers. I didn't faced any problems to achieve this with layer-1 and layer-2. But, I'm not sure how to make communication layer to use this common declaration dll. Your suggestion would help me to design my application better. Thanks in advance Regards ArunDhaJ

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  • c#3.5 Deserialization error - object reference not set

    - by BBR
    I am trying to deserialize an xml string in c#3.5, the code below does work in c# 4.0. When I try to run in the code in c#3.5 I get an Object reference not set to an instance of an object exception when the code tries in initialize the XmlSerializer. Any help would be appreciated. string xml = "<boolean xmlns=\"http://schemas.microsoft.com/2003/10/serialization/\">false</boolean>"; var xSerializer = new XmlSerializer(typeof(bool), null, null, new XmlRootAttribute("boolean"), "http://schemas.microsoft.com/2003/10/serialization/"); using (var sr = new StringReader(xml)) using (var xr = XmlReader.Create(sr)) { var y = xSerializer.Deserialize(xr); } System.NullReferenceException was unhandled Message="Object reference not set to an instance of an object." Source="System.Xml" StackTrace: at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace, String location, Evidence evidence) at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace) .... at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException:

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  • SWIG interface to receive an opaque struct reference in Java through function argument

    - by Beeo
    I am trying to use SWIG in order to use the Spotify API (libspotify) for Android: https://developer.spotify.com/technologies/libspotify/ I am having trouble defining the SWIG interface file to be able to successfully call the following native C function: sp_error sp_session_create(const sp_session_config * config, sp_session ** sess); Which in C would be called like this: //config struct defined previously sp_session *sess; sp_session_create(&config, &sess); But in Java I would need to call it like this: //config object defined previously sp_session javaSess = new sp_session(); sp_session_create(config, javaSess); sp_session is an opaque struct and is only defined in libspotify's API.h file as: typedef struct sp_session sp_session; I'm expecting the libspotify library to create it and give me a reference to it. The only thing I need that reference for then is to pass to other functions in the API. I believe the answer lies within the SWIG interface and typemaps, but I have been unsuccessful in trying to apply the examples I found in the documentation: http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_struct_pointer_pointer `http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_using_typemaps_return_arguments Help!

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  • Copy constructor called even when returning by reference?

    - by Johnyy
    Hi, I am testing the return of local objects by reference. My original test went well but something else happens unexpected. #include <iostream> using namespace std; class MyInt { public: MyInt(int i){ value = new int(i); } ~MyInt(){ delete value; } int getValue(){ return *value; } MyInt(const MyInt &b){ cout<<"Copy"<<endl; } private: int* value; }; MyInt& returnref(){ MyInt a(10); cout<<"Returning from returnref()"<<endl; return a; } int main(){ MyInt a = returnref(); cout<<a.getValue()<<endl; return 0; } My console prints "Returning from ..." then "Copy" then a random value. My understanding of pass by reference is that it does not need to make any copy. Why is it not doing what I expected?

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  • Reference to the Main Form whilst trying to Serialize objects in C#

    - by Paul Matthews
    I have a button on my main form which calls a method to serialize some objects to disk. I am trying to add these objects to an ArrayList and then serialize them using a BinaryFormatter and a FileStream. public void SerializeGAToDisk(string GenAlgName) { // Let's make a list that includes all the objects we // need to store a GA instance ArrayList GAContents = new ArrayList(); GAContents.Add(GenAlgInstances[GenAlgName]); // Structure and info for a GA GAContents.Add(RunningGAs[GenAlgName]); // There may be several running GA's using (FileStream fStream = new FileStream(GenAlgName + ".ga", FileMode.Create, FileAccess.Write, FileShare.None)) { BinaryFormatter binFormat = new BinaryFormatter(); binFormat.Serialize(fStream, GAContents); } } When running the above code I get the following exception: System.Runtime.Serialization.SerializationException was unhandled Message=Type 'WindowsFormsApplication1.Form1' in Assembly 'GeneticAlgApp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' is not marked as serializable. So that means that somewhere in the objects I'm trying to save there must be a reference to the main form. The only possible references I can see are 3 delegates which all point to methods in the main form code. Do delegates get serialized as well? I can't seem to apply the [NonSerialized] attribute to them. Is there anything else I might be missing? Even better, is there a quick method to find the reference(s) that are causing the problem?

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  • Web Reference Code generator template.

    - by Bluephlame
    I Have an internal SOAP Web service that is being called from an external REST service in .NET it works fine however I am simply passing through the SOAP objects of the REST Layer but the automatic generation of the WebReference Code in Visual Studio adds the 'field' to the end of every attribute. basically it makes my XML look all nasty. Everything works I just want to clean up my XML. Any ideas how i can change the template for the reference.cs or to make the XML generate nicely from the Web Service Objects. Here is an example of the reference.cs public int HeadLeft { get { return this.headLeftField; } set { this.headLeftField = value; } } /// <remarks/> public int HeadTop { get { return this.headTopField; } set { this.headTopField = value; } } /// <remarks/> public int HeadWidth { get { return this.headWidthField; } set { this.headWidthField = value; } } Here is an examle of the XML <a:headHeightField>208</a:headHeightField> <a:headLeftField>316</a:headLeftField> <a:headTopField>103</a:headTopField> <a:headWidthField>161</a:headWidthField>

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