Search Results

Search found 11221 results on 449 pages for 'pure virtual'.

Page 409/449 | < Previous Page | 405 406 407 408 409 410 411 412 413 414 415 416  | Next Page >

  • C++ MFC server app with sockets crashes and I cannot find the fault, help!

    - by usermeister
    My program has one dialog and two sockets. Both sockets are derived from CAsyncSocket, one is for listening, other is for receiving data from client. My program crashes when client tries to connect to server application and server needs to initialize receiving socket. This is my MFC dialog class. class CFileTransferServerDlg : public CDialog { ... ListeningSocket ListenSock; ReceivingSocket* RecvSock; void OnAccept(); // called when ListenSock gets connection attempt ... }; This is my derived socket class for receiving data that calls parent dialogs method when event is signaled. class ReceivingSocket : public CAsyncSocket { CFileTransferServerDlg* m_pDlg; // for accessing parent dialogs controls virtual void OnReceive(int nErrorCode); } ReceivingSocket::ReceivingSocket() { } This is dialogs function that handles incoming connection attempt when listening socket gets event notification. This is where the crash happens. void CFileTransferServerDlg::OnAccept() { RecvSock = new ReceivingSocket; /* CRASH */ } OR void CFileTransferServerDlg::OnAccept() { ReceivingSocket* tmpSock = new ReceivingSocket; tmpSock->SetParentDlg(this); CString message; if( ListenSock.Accept(*tmpSock) ) /* CRASH */ { message.LoadStringW(IDS_CLIENT_CONNECTED); m_txtStatus.SetWindowTextW(message); RecvSock = tmpSock; } } My program crashes when I try to create a socket for receiving file sent from client application. OnAccept starts when Listening socket signals incoming connection attempt, but my application then crashes. I've tried running it on another computer and connection attempt was succesful. What could be wrong? Error in debug mode: Unhandled exception at 0x009c30e1 in FileTransferServer.exe: 0xC0000005: Access violation reading location 0xccccce58.

    Read the article

  • Google maps and J-Query: Individual markers?

    - by user351189
    Hi there, I have created a Google maps mashup, where with a bit of input, I have managed to have a sidebar that links to a video icon/marker that then opens up an info window showing virtual tours. I would, however, like to put different coloured marker icons on the map depending on the category that the video is in. This would be easy enough to do, but my page is made up of a mixture of J-Query and JavaScript all calling to the individual flash files. Could someone help me with the code for adding extra marker icons for different categories? Here is the code: So, after the intial 'var camera;' point, there comes this: function addMarker(point, title, video, details) { var marker = new GMarker(point, {title: title, icon:camera}); GEvent.addListener(marker, "click", function() { if (details) { marker.openInfoWindowTabsHtml([new GInfoWindowTab("Video", video), new GInfoWindowTab("More", details)]); } else { marker.openInfoWindowHtml(video); } }); Then further down, is the code for calling the individual marker image. I would like to add another image to this list - would I start out by calling the new object 'camera-red.image' or something similar? function initialize() { if (GBrowserIsCompatible()) { map = new GMap2(document.getElementById("mapDiv")); map.setCenter(new GLatLng(51.52484592590448, -0.13345599174499512), 17); map.setUIToDefault(); var uclvtSatMapType = createUclVTSatMapType() map.addMapType(uclvtSatMapType); map.setMapType(uclvtSatMapType); camera = new GIcon(G_DEFAULT_ICON); camera.image = "ucl-video.png"; camera.iconSize = new GSize(32,37); camera.iconAnchor = new GPoint(16,35); camera.infoWindowAnchor = new GPoint(16,2); addMarkersToMap(); } The actual map can be found here: link text Thanks. Gray

    Read the article

  • Is it theoretically possible to emulate a human brain on a computer?

    - by JoelK
    Our brain consists of billions of neurons which basically work with all the incoming data from our senses, handle our consciousness, emotions and creativity as well as our hormone system, etc. So I'm completely new to this topic but doesn't each neuron have a fixed function? E.g.: If a signal of strength x enters, if the last signal was x ms ago, redirect it. From what I've learned in biology about our nerves system which includes our brain because both consist of simple neurons, it seems to me as our brain is one big, complicated computer. Maybe so complicated that things such as intelligence and cognition become possible? As the most complicated things about a neuron pretty much are the chemical aspects on generating an electric singal, keeping itself alive, and eventually segmenting itself, it should be pretty easy emulating some on a computer, or? You won't have to worry about keeping your virtual neuron alive, or? If you can emulate a single neuron on a computer, which shouldn't be too hard, could you theoretically emulate more than 1000 billions of them, recreating intelligence, cognition and maybe even creativity? In my question I'm leaving out the following aspects: Speed of our current (super) computers Actually writing a program for emulating neurons I don't know much about this topic, please tell me if I got anything wrong :) (My secret goal: Make a copy of my brain and store it on some 10 million TB HDD and make someone start it up in the future)

    Read the article

  • Is method reference caching a good idea in Java 8?

    - by gexicide
    Consider I have code like the following: class Foo { Y func(X x) {...} void doSomethingWithAFunc(Function<X,Y> f){...} void hotFunction(){ doSomethingWithAFunc(this::func); } } Consider that hotFunction is called very often. Would it then be advisable to cache this::func, maybe like this: class Foo { Function<X,Y> f = this::func; ... void hotFunction(){ doSomethingWithAFunc(f); } } As far as my understanding of java method references goes, the Virtual Machine creates an object of an anonymous class when a method reference is used. Thus, caching the reference would create that object only once while the first approach creates it on each function call. Is this correct? Should method references that appear at hot positions in the code be cached or is the VM able to optimize this and make the caching superfluous? Is there a general best practice about this or is this highly VM-implemenation specific whether such caching is of any use?

    Read the article

  • Reload mod_fcgid without killing Python Service

    - by Tobias
    Hi I'm currently running a Django project on my school's webserver with FCGI. I did follow the multiple guides that recommends installing a virtual local Python environment and it worked out great. The only issue i had was that "touching" my fcgi-file to reload source-files wasn't enough, but instead i had to kill the python service via SSH. This because mod_fcgid is used. However, the admin didn't think it was a great idea that i ran my own local python. He thought it better if i just told him what modules to install on root, which was a pretty nice service really. But doing this, i can no longer kill python since it's under root(though immoral as I am, I've definitely tried). The admins recommendation was that I should try too make the fcgi script reload itself by checking time stamp. I've tried to find documentation on how to do this, but fund very little and since I'm a absolute beginner i have no idea what would work. Anyone have experience running python/django under mod_fcgid or tips on where to find related guides/documentation?

    Read the article

  • Zend dubugger in eclipse - timeout everytime

    - by jax
    I am running a virtual server in the US. I am trying to get my eclipse machine at home (outside the USA), to connect to the USA server. I have setup Zend on the server. When I run phpinfo() I get the following zend output. Note: 1.2.3.4 will be the external WAN IP address of my ADSL router at home. Directive Local Value Master Value zend_debugger.allow_hosts 127.0.0.1,1.2.3.4 127.0.0.1,1.2.3.4 zend_debugger.allow_tunnel no value no value zend_debugger.deny_hosts no value no value zend_debugger.expose_remotely always always zend_debugger.httpd_uid -1 -1 zend_debugger.max_msg_size 2097152 2097152 zend_debugger.tunnel_max_port 65535 65535 zend_debugger.tunnel_min_port 1024 1024 So zend looks like it is working ok on the server side. When I run a debug session and select 'Test Debugger' I get a timeout every time. I have already added dummy.php to the root folder of the server. In 'installed debuggers' I double clicked on Zend and have put my external WAN IP address. I noticed that the port is 10000, I also have webmin running on this port on the server, will there be a conflict?

    Read the article

  • Android SDK: Hello World won't run !

    - by RedRoses
    Hello, This is a very very beginner question regarding Android Development I am trying to create and run the Hello world example from the Android SDK website, but I can't see anything appearing on the screen. It appears to me that Eclipse just hangs at this point: [2010-11-05 09:55:47 - HelloAndroid] ------------------------------ [2010-11-05 09:55:47 - HelloAndroid] Android Launch! [2010-11-05 09:55:47 - HelloAndroid] adb is running normally. [2010-11-05 09:55:47 - HelloAndroid] Performing com.example.helloandroid.HelloAndroid activity launch [2010-11-05 09:55:48 - HelloAndroid] Automatic Target Mode: launching new emulator with compatible AVD 'AVD2' [2010-11-05 09:55:48 - HelloAndroid] Launching a new emulator with Virtual Device 'AVD2' [2010-11-05 09:55:51 - HelloAndroid] New emulator found: emulator-5554 [2010-11-05 09:55:51 - HelloAndroid] Waiting for HOME ('android.process.acore') to be launched... [2010-11-05 09:57:10 - HelloAndroid] WARNING: Application does not specify an API level requirement! [2010-11-05 09:57:10 - HelloAndroid] Device API version is 8 (Android 2.2) [2010-11-05 09:57:10 - HelloAndroid] HOME is up on device 'emulator-5554' [2010-11-05 09:57:10 - HelloAndroid] Uploading HelloAndroid.apk onto device 'emulator-5554' [2010-11-05 09:57:12 - HelloAndroid] Installing HelloAndroid.apk... [2010-11-05 09:59:33 - HelloAndroid] Success! [2010-11-05 09:59:33 - HelloAndroid] Starting activity com.example.helloandroid.HelloAndroid on device emulator-5554 So it says "Starting activity ..." but nothing ever starts and it's already been more than 30 mins. What could be wrong?? Thanks !

    Read the article

  • mod_rewrite: no access to real files and directories

    - by tshabalala
    Hello. I use mod_rewrite/.htaccess for pretty URLs. I forward all the requests to my index.php, like this: RewriteRule ^/?([a-zA-Z0-9/-]+)/?$ /index.php [NC,L] The index.php then handles the requests. I'm also using this condition/rule to eliminate trailing slashes (or rather rewrite them to the URL without a trailing slash, with a 301 redirect; I'm doing this to avoid duplicate content and because I like no trailing slashes better): RewriteCond %{HTTP_HOST} !^\.localhost$ [NC] RewriteRule ^(.+)/$ http://%{HTTP_HOST}/$1 [R=301,L] This works well, except that I now get an infinite loop when trying to access a (real) directory (the rewrite rule removes the trailing slash, the server adds it again, ...). I solved this by setting the DirectorySlash directive to Off: DirectorySlash Off I don't know how good this solution is, I don't feel too confident about it tbh. Anyway, what I'd like to do is completely ignore "real" files and directories, since I don't need them and I only use pretty URLs with "virtual" files/directories anyway. This would allow me to avoid the DirectorySlash workaround/hack too. Is this possible? Thanks!

    Read the article

  • Call 32-bit or 64-bit program from bootloader

    - by user1002358
    There seems to be quite a lot of identical information on the Internet about writing the following 3 bootloaders: Infinite loop jmp $ Print a single character Print "Hello World". This is fantastic, and I've gone through these 3 variations with very little trouble. I'd like to write some 32- or 64-bit code in C and compile it, and call that code from the bootloader... basically a bootloader that, for example, sets the computer up to run some simple numerical simulation. I'll start by listing primes, for example, and then maybe some input/output from the user to maybe compute a Fourier transform. I don't know. I haven't found any information on how to do this, but I can already foresee some problems before I even begin. First of all, compiling a C program compiles it into one of several different files, depending on the target. For Windows, it's a PE file. For Linux, it's a .out file. These files are both quite different. In my instance, the target isn't Windows or Linux, it's just whatever I have written in the bootloader. Secondly, where would the actual code reside? The bootloader is exactly 512 bytes, but the program I write in C will certainly compile to something much larger. It will need to sit on my (virtual) hard disk, probably in some sort of file system (which I haven't even defined!) and I will need to load the information from this file into memory before I can even think about executing it. But from my understanding, all this is many, many orders of magnitude more complex than a 12-line "Hello World" bootloader. So my question is: How do I call a large 32- or 64-bit program (written in C/C++) from my 16-bit bootloader.

    Read the article

  • implementation musical instrument using audio unit

    - by Develop.Kim
    post same question at apple developer forum ,too hi first sorry that my english is poor.. i want develop iphone application that playing musical instrument like 'ocarina' but don't need blow mic features. so first i tried to find that how implementation 'virtual musical instrument ' in iphone development. the during the decide implementation using 'Audio Unit' to report this article (link) so i want two kind of questions. i recognize that the 'musical instrument' can be divided into three sound that 'attack', 'sustain' , 'release'. 'decay' maybe included (link) . How implementation when audio unit base 'AUInstrumentBase' each sound ? i download sample 'SinSynth' (link) . i want play note this instrument unit for analyze source and study. Is there way to using AULab? expected the way using MIDI input . but i don't have MIDI. in addition, i wonder that i would think it right the way. to ask the advice... thank for reading poor english my article.

    Read the article

  • How to secure connection strings in VS?

    - by salvationishere
    I see several others have posted this question, however, none of the solutions I've tried have fixed this yet. I have a 32-bit XP running VS 2008 and I am trying to encrypt my connection string in my web.config file. But I am getting the error: The configuration section '...' was not found. Failed! The command I give it: C:\Program Files\Microsoft Visual Studio 9.0\VCAspnet_regiis.exe -pe "system.we b/AdventureWorksConnectionString2" -app "/Documents and Settings/Admin/My Docume nts/Visual Studio 2008/Projects/AddFileToSQL2" Also, how does -app map virtual directory? In other words the path above is the directory right below c:. Is this the correct path to use? And AddFileToSQL2 is the name of my project, although it is part of the AddFileToSQL solution. I have this folder web shared with all of the permissions. And the relevant part of my web.config file: <add name="AdventureWorksConnectionString2" connectionString="Data Source=SIDEKICK;Initial Catalog=AdventureWorks;Persist Security Info=true; User ID=AdventureWorks;Password=sqlMagic" providerName="System.Data.SqlClient" />

    Read the article

  • Why can a public class not inherit from a less visible one?

    - by Dan Tao
    I apologize if this question has been asked before. I've searched SO somewhat and wasn't able to find it. I'm just curious what the rationale behind this design was/is. Obviously I understand that private/internal members of a base type cannot, nor should they, be exposed through a derived public type. But it seems to my naive thinking that the "hidden" parts could easily remain hidden while some base functionality is still shared and a new interface is exposed publicly. I'm thinking of something along these lines: Assembly X internal class InternalClass { protected virtual void DoSomethingProtected() { // Let's say this method provides some useful functionality. // Its visibility is quite limited (only to derived types in // the same assembly), but at least it's there. } } public class PublicClass : InternalClass { public void DoSomethingPublic() { // Now let's say this method is useful enough that this type // should be public. What's keeping us from leveraging the // base functionality laid out in InternalClass's implementation, // without exposing anything that shouldn't be exposed? } } Assembly Y public class OtherPublicClass : PublicClass { // It seems (again, to my naive mind) that this could work. This class // simply wouldn't be able to "see" any of the methods of InternalClass // from AssemblyX directly. But it could still access the public and // protected members of PublicClass that weren't inherited from // InternalClass. Does this make sense? What am I missing? }

    Read the article

  • Events + Adapter Pattern

    - by Stretto
    I have an adapter pattern on a generic class that essentially adapts between types: class A<T> { event EventHandler e; } class Aadapter<T1, T2> : A<T1> { A<T2> a; Aadapter(A<T2> _a) { a = _a; } } The problem is that A contains an event. I effectively want all event handlers assigned to Adapter to fall through to a. It would be awesome if I could assign the a's event handler to adapter's event handler but this is impossible? The idea here is that A is almost really just A but we need a way to adapt the them. Because of the way event's work I can't how to efficiently do it except manually add two event handlers and when they are called they "relay" the to the other event. This isn't pretty though and it would seem much nicer if I could have something like class A<T> { event EventHandler e; } class Aadapter<T1, T2> : A<T1> { event *e; A<T2> a; Aadapter(A<T2> _a) { a = _a; e = a.e; } } in a sense we have a pointer to the event that we can assign a2's event to. I doubt there is any simple way but maybe someone has some idea to make it work. (BTW, I realize this is possible with virtual events but I'd like to avoid this if at all possible)

    Read the article

  • Is it OK to set state within Event Raising methods?

    - by Greg
    I ran across this pattern in the code of a library I'm using. It sets state within the event raising method, but only if the event is not null. protected virtual void OnMyEvent(EventArgs e) { if(MyEvent != null) { State = "Executing"; // Only sets state if MyEvent != null. MyEvent(this,e); } } Which means that the state is not set when overriding the method: protected override void OnMyEvent(EventArgs e) { base.OnMyEvent(e); Debug.Assert( State == "Executing" ); // This fails } but is only set when handling the event: foo.MyEvent += (o, args) => Debug.Assert(State == "Executing"); // This passes Setting state within the if(MyEvent != null) seems like bad form, but I've checked the Event Design Guidelines and it doesn't mention this. Do you think this code is incorrect? If so, why? (Reference to design guidelines would be helpful). Edit for Context: It's a Control, I'm trying to create subclass of it, and the state that it's setting is calling EnsureChildControls() conditionally based upon there being an event handler. I can call EnsureChildControls() myself, but I consider that something of a hack.

    Read the article

  • Windows: Does something temporarily grab the com ports on startup?

    - by Tim
    I have a WPF/C# app that is launched as part of the "Startup" group on a Windows Embedded Standard machine. One of the first things the app does (in its static App() method) is create a new SerialPort object for COM1. COM1 is a hardwired serial port, not a USB virtual port or anything like that. My problem is that every so often (maybe 1 out of 12) on startup, I get an exception: System.UnauthorizedAccessException: Access to the port 'COM1' is denied. There are no other applications using this port. Also, when I relaunch the app following this error, it grabs the port just fine. It's as if the com port isn't ready/set up for my app sometimes. I'm clueless on this one! Any insight is appreciated! UPDATE: I added a call to SerialPort.GetPortNames() and printout all available ports before attempting to open the port. In the failure case COM1 is indeed THERE! So, it's not that the port isn't ready. It looks like something in Windows is actually grabbing the port temporarily and blocking me.

    Read the article

  • LINQ to SQL Queries odd Materialization

    - by ptoinson
    I ran across an interesting Linq to SQL, uh, feature, the other day. Perhaps someone can give me a logical explanation for the reasoning behind the results. Take the code below as my example which utilizes the AdventureWorks database setup in a Linq to SQL DataContext. This is a clip from my unit test. The resulting customer returned from a call to both CustomerQuery_Test_01() and CustomerQuery_Test_02() is the same. However, the query executed on the SQLServer are different is a major way. The method CustomerQuery_Test_01 us causing the entire Customer table to be materialized, which the call to CustomerQuery_Test_02 is only causing the single customer to be materialized. The resulting SQL Queries are at the bottom of this post. Anyone have a good reason for this? To me, it was highly non-intuitive. protected virtual Customer GetByPrimaryKey(Func<Customer, bool> keySelection) { AdventureWorksDataContext context = new AdventureWorksDataContext(); return (from r in context.Customers select r).SingleOrDefault(keySelection); } [TestMethod] public void CustomerQuery_Test_01() { Customer customer = GetByPrimaryKey(c => c.CustomerID == 2); } [TestMethod] public void CustomerQuery_Test_02() { AdventureWorksDataContext context = new AdventureWorksDataContext(); Customer customer = (from r in context.Customers select r).SingleOrDefault(c => c.CustomerID == 2); } Query for CustomerQuery_Test_01 (notice the lack of a where clause) SELECT [t0].[CustomerID], [t0].[NameStyle], [t0].[Title], [t0].[FirstName], [t0].[MiddleName], [t0].[LastName], [t0].[Suffix], [t0].[CompanyName], [t0].[SalesPerson], [t0].[EmailAddress], [t0].[Phone], [t0].[PasswordHash], [t0].[PasswordSalt], [t0].[rowguid], [t0].[ModifiedDate] FROM [SalesLT].[Customer] AS [t0] Query for CustomerQuery_Test_02 (notice the where clause) SELECT [t0].[CustomerID], [t0].[NameStyle], [t0].[Title], [t0].[FirstName], [t0].[MiddleName], [t0].[LastName], [t0].[Suffix], [t0].[CompanyName], [t0].[SalesPerson], [t0].[EmailAddress], [t0].[Phone], [t0].[PasswordHash], [t0].[PasswordSalt], [t0].[rowguid], [t0].[ModifiedDate] FROM [SalesLT].[Customer] AS [t0] WHERE [t0].[CustomerID] = @p0

    Read the article

  • How to limit Access-Control-Allow-Origin to a specific path?

    - by coderama
    I have a website that servies ads via javascript. So, I basically allow the user to include my script.... : <script src="http://www.example.com/ads.js" ></script> <script> MYADDS.insertAdvert(); </script> The problem is, I kept getting: "No Access-Control-Allow-Origin" Errors. That was until I added this to my htaccess file: <IfModule mod_headers.c> Header set Access-Control-Allow-Origin "*" </IfModule> Problem is, this opens up my entire site and is probably a security risk. So, seeing as the ads.js file actually only does an ajax request to: http://www.example.com/place/where/my/adds/are/fed/from How can I make the above htaccess rule only apply to that path? Keep in mind, it's not an actualy directory, so I can't put the htaccess file in that folder. It's actually a "virtual path". The site is built using Laravel and therefore does the typical laravel path rewriting. Here's teh full htaccess file: <IfModule mod_rewrite.c> <IfModule mod_negotiation.c> Options -MultiViews </IfModule> RewriteEngine On # Redirect Trailing Slashes... RewriteRule ^(.*)/$ /$1 [L,R=301] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php/$1 [L] </IfModule> Any ideas how to do this?

    Read the article

  • Implementing a Version check between an Abstract class and it's implementation

    - by Michael Stum
    I have this abstract class and concrete implementation (they are in different assemblies): public abstract class MyAbstractClass { private static readonly int MyAbstractClassVersion = 1; public abstract int ImplementedVersion { get; } protected MyAbstractClass() { CheckVersion(); } private void CheckVersion() { var message = string.Format( "MyAbstractClass implements Version {0}, concrete is Version {1}", RepositoryVersion, ImplementedVersion); if (!MyAbstractClassVersion.Equals(ImplementedVersion)) throw new InvalidOperationException(message); } } public class ConcreteClass : MyAbstractClass { public ConcreteClass() : base() { // ConcreteClass is guaranteed to have // a constructor that calls the base constructor // I just simplified the example } public override int ImplementedVersion { get { return 2; } } } As you see, I call CheckVersion() from the abstract constructor, to get rid of the "virtual member call in base constructor" message, but I am not sure if that's really the way to do it. Sure, it works, but that doesn't mean it will always work, will it? Also, I wonder if I can get the name of the Concrete Type from the CheckVersion() function? I know that adding new abstract members will force an error anyway (System.TypeLoadException) and I'm not sure if I want this type of strict Versioning, but I'm just curious how it would be done properly given only the abstract class and an implementation (I know I could do it by using interfaces and/or a Factory pattern).

    Read the article

  • C++ templates error: instantiated from 'void TestClass::testMethod(T, std::map) [with T = SomeClass]

    - by pureconsciousness
    Hello there, I've some problem in my code I cannot deal with: #ifndef TESTCLASS_H_ #define TESTCLASS_H_' #include <map> using namespace std; template <typename T> class TestClass { public: TestClass(){}; virtual ~TestClass(){}; void testMethod(T b,std::map<T,int> m); }; template <typename T> void TestClass`<T`>::testMethod(T b,std::map<T,int> m){ m[b]=0; } #endif /*TESTCLASS_H_*/ int main(int argc, char* argv[]) { SomeClass s; TestClass<SomeClass> t; map<SomeClass,int> m; t.testMethod(s,m); } Compiler gives me following error in line m[b]=0; : instantiated from 'void TestClass::testMethod(T, std::map) [with T = SomeClass] Could you help find the problem?? Thanks in advance

    Read the article

  • ref and out parameters in C# and cannot be marked as variant.

    - by Water Cooler v2
    What does the statement mean? From here ref and out parameters in C# and cannot be marked as variant. 1) Does it mean that the following can not be done. public class SomeClass<R, A>: IVariant<R, A> { public virtual R DoSomething( ref A args ) { return null; } } 2) Or does it mean I cannot have the following. public delegate R Reader<out R, in A>(A arg, string s); public static void AssignReadFromPeonMethodToDelegate(ref Reader<object, Peon> pReader) { pReader = ReadFromPeon; } static object ReadFromPeon(Peon p, string propertyName) { return p.GetType().GetField(propertyName).GetValue(p); } static Reader<object, Peon> pReader; static void Main(string[] args) { AssignReadFromPeonMethodToDelegate(ref pReader); bCanReadWrite = (bool)pReader(peon, "CanReadWrite"); Console.WriteLine("Press any key to quit..."); Console.ReadKey(); } I tried (2) and it worked.

    Read the article

  • Doubt on pointer conversion

    - by Simone
    Suppose we have the following code: #include <iostream> struct A { virtual void f() { std::cout << "A::f()" << std::endl; } }; struct B: A { void f() { std::cout << "B::f()" << std::endl; } }; void to_A(void* voidp) { A* aptr = static_cast<A*>(voidp); aptr->f(); } void to_B(void* voidp) { B* bptr2 = static_cast<B*>(voidp); bptr2->f(); } int main() { B* bptr = new B; void* voidp = bptr; to_A(voidp); // prints B::f() to_B(voidp); // prints B::f() } is this code guaranteed to always work as in the code comments or is it UB? AFAIK it should be ok, but I'd like to be reassured.

    Read the article

  • which sql consumes less memory

    - by prmatta
    Yesterday I asked a question on how to re-write sql to do selects and inserts in batches. I needed to do this to try and consume less virtual memory, since I need to move millions of rows here. The object is to move rows from Table B into Table A. Here are the ways I can think of doing this: SQL #1) INSERT INTO A (x, y, z) SELECT x, y, z FROM B b WHERE ... SQL #2) FOREACH SELECT x,y,z FROM B b WHERE ... INSERT INTO A(x,y,z); END FOREACH; SQL #3) FOREACH SELECT FIRST 2000 x,y,z FROM B b WHERE ... INSERT INTO A(x,y,z); END FOREACH; SQL #4) FOREACH SELECT FIRST 2000 x,y,z FROM B b WHERE ... AND NOT EXISTS IN (SELECT * FROM A) INSERT INTO A(x,y,z); END FOREACH; Are any of the above incorrect? The database is informix 11.5.

    Read the article

  • Globally define parts of virtualhost definition to reduce redundancy

    - by user1428900
    I have setup an apache server and this apache server points to a bunch of virtualhosts. The definition of the virtualhosts are as follows, <VirtualHost *:80> ServerName <url> RewriteEngine on ReWriteCond %{SERVER_PORT} !^443$ RewriteRule ^/(.*) https://%{HTTP_HOST}/$1 [NC,R,L] # Enable client-side caching of resources ExpiresActive On ExpiresByType image/png "now plus 48 hours" ExpiresByType image/jpeg "now plus 48 hours" ExpiresByType image/gif "now plus 48 hours" ExpiresByType application/javascript "now plus 48 hours" ExpiresByType application/x-javascript "now plus 48 hours" ExpiresByType text/javascript "now plus 48 hours" ExpiresByType text/css "now plus 48 hours" </VirtualHost> . . . <VirtualHost *:80> ServerName <url> RewriteEngine on ReWriteCond %{SERVER_PORT} !^443$ RewriteRule ^/(.*) https://%{HTTP_HOST}/$1 [NC,R,L] # Enable client-side caching of resources ExpiresActive On ExpiresByType image/png "now plus 48 hours" ExpiresByType image/jpeg "now plus 48 hours" ExpiresByType image/gif "now plus 48 hours" ExpiresByType application/javascript "now plus 48 hours" ExpiresByType application/x-javascript "now plus 48 hours" ExpiresByType text/javascript "now plus 48 hours" ExpiresByType text/css "now plus 48 hours" </VirtualHost> I have a ton of virtual host definitions similar to the examples shown above. Since, most of the definitions other than the ServerName are the same, I was wondering if there was a way to define these common definitions globally. I am new to apache configuration and I felt that as the number of virtualhost definitions increase my configuration file becomes longer and redundant.

    Read the article

  • Why does the VS2005 debugger not report "base." values properly? (was "Why is this if statement fail

    - by Rawling
    I'm working on an existing class that is two steps derived from System.Windows.Forms.Combo box. The class overrides the Text property thus: public override string Text { get { return this.AccessibilityObject.Value; } set { if (base.Text != value) { base.Text = value; } } } The reason given for that "get" is this MS bug: http://support.microsoft.com/kb/814346 However, I'm more interested in the fact that the "if" doesn't work. There are times where "base.Text != value" is true and yet pressing F10 steps straight to the closing } of the "set" and the Text property is not changed. I've seen this both by just checking values in the debugger, and putting a conditional breakpoint on that only breaks when the "if" statement's predicate is true. How on earth can "if" go wrong? The class between this and ComboBox doesn't touch the Text property. The bug above shouldn't really be affecting anything - it says it's fixed in VS2005. Is the debugger showing different values than the program itself sees? Update I think I've found what is happening here. The debugger is reporting value incorrectly (including evaluating conditional breakpoints incorrectly). To see this, try the following pair of classes: class MyBase { virtual public string Text { get { return "BaseText"; } } } class MyDerived : MyBase { public override string Text { get { string test = base.Text; return "DerivedText"; } } } Put a breakpoint on the last return statement, then run the code and access that property. In my VS2005, hovering over base.Text gives the value "DerivedText", but the variable test has been correctly set to "BaseText". So, new question: why does the debugger not handle base properly, and how can I get it to?

    Read the article

  • One-to-many Associations Empty Columns Issue (Ext on Rails)

    - by Joe
    I'm playing with rewriting part of a web application in Rails + Ext. However, I'm having trouble getting an associated models' name to display in the grid view. I've been able to successfully convert several models and arrange the views nicely using tabs and Ext's layout helpers. However, I'm in the middle of setting up an association -- I've followed along with Jon Barket's tutorial on how to do this using Ext -- and I've made all the Rails and JS changes suggested (with appropriate name changes for my models,) the result being that the combo box is now being correctly populated with the names of the associated models, and changes are actually written correctly to database, BUT the data doesn't show up in the column, it's just empty. However, the correct data is there in the 'detail' view. Really just wondering if anyone else ran into this, or had any thoughts on what could be happening. Definitely willing to post code if requested; just note that (AFAIK) my changes follow the tutorial pretty closely. Thanks in advance! UPDATE: Alright, slight progress - kind of. I can get the associated model id # displaying properly -- just by modifying the column model slightly. But I can't get the virtual attribute displayed in the main table (in Jon's example it's country_name.) It still goes blank when I change the data source for that column from dataIndex: 'model[associated_model_id]' to dataIndex: 'virtual_attributes[associated_model_name]' ANOTHER UPDATE: Bump. Has NOBODY here tried integrating Ext with Rails?

    Read the article

< Previous Page | 405 406 407 408 409 410 411 412 413 414 415 416  | Next Page >