Search Results

Search found 22900 results on 916 pages for 'pascal case'.

Page 193/916 | < Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >

  • error LNK2001: unresolved external symbol

    - by numerical25
    I am receiving this error >GXRenderManager.obj : error LNK2001: unresolved external symbol "private: static class GXRenderer * GXRenderManager::renderDevice" (?renderDevice@GXRenderManager@@0PAVGXRenderer@@A) The following is my code... GXDX.h class GXDX: public GXRenderer { public: void Render(); void StartUp(); }; GXGL.h class GXGL: public GXRenderer { public: void Render(); void StartUp(); }; GXRenderer class GXRenderer { public: virtual void Render() = 0; virtual void StartUp() = 0; }; GXRenderManager.h #ifndef GXRM #define GXRM #include <windows.h> #include "GXRenderer.h" #include "GXDX.h" #include "GXGL.h" enum GXDEVICE { DIRECTX, OPENGL }; class GXRenderManager { public: static int Ignite(GXDEVICE); private: static GXRenderer *renderDevice; }; #endif GXRenderManager.cpp #include "GXRenderManager.h" int GXRenderManager::Ignite(GXDEVICE DeviceType) { switch(DeviceType) { case DIRECTX: GXRenderManager::renderDevice = new GXDX; return 1; break; case OPENGL: GXRenderManager::renderDevice = new GXGL; return 1; break; default: return 0; } } main.cpp #include "GXRenderManager.h" int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { return 0; } I am not trying to get it to do anything. I am just trying to compile with no errors. I am new with all this so if anyone can give me a hand. that will be great. thanks

    Read the article

  • Entity Framework and differences between Contains between SQL and objects using ToLower

    - by John Ptacek
    I have run into an "issue" I am not quite sure I understand with Entity Framework. I am using Entity Framework 4 and have tried to utilize a TDD approach. As a result, I recently implemented a search feature using a Repository pattern. For my test project, I am implementing my repository interface and have a set of "fake" object data I am using for test purposes. I ran into an issue trying to get the Contains clause to work for case invariant search. My code snippet for both my test and the repository class used against the database is as follows: if (!string.IsNullOrEmpty(Description)) { items = items.Where(r => r.Description.ToLower().Contains(Description.ToLower())); } However, when I ran my test cases the results where not populated if my case did not match the underlying data. I tried looking into what I thought was an issue for a while. To clear my mind, I went for a run and wondered if the same code with EF would work against a SQL back end database, since SQL will explicitly support the like command and it executed as I expected, using the same logic. I understand why EF against the database back end supports the Contains clause. However, I was surprised that my unit tests did not. Any ideas why other than the SQL server support of the like clause when I use objects I populate in a collection instead of against the database server? Thanks! John

    Read the article

  • JSP: How can I still get the code on my error page to run, even if I can't display it?

    - by Josh Hinman
    I've defined an error-page in my web.xml: <error-page> <exception-type>java.lang.Exception</exception-type> <location>/error.jsp</location> </error-page> In that error page, I have a custom tag that I created. The tag handler for this tag e-mails me the stacktrace of whatever error occurred. For the most part this works great. Where it doesn't work great is if the output has already begun being sent to the client at the time the error occurs. In that case, we get this: SEVERE: Exception Processing ErrorPage[exceptionType=java.lang.Exception, location=/error.jsp] java.lang.IllegalStateException I believe this error happens because we can't redirect a request to the error page after output has already started. The work-around I've used is to increase the buffer size on particularly large JSP pages. But I'm trying to write a generic error handler that I can apply to existing applications, and I'm not sure it's feasible to go through hundreds of JSP pages making sure their buffers are big enough. Is there a way to still allow my stack trace e-mail code to execute in this case, even if I can't actually display the error page to the client?

    Read the article

  • Are MEF's ComposableParts contracts instance-based?

    - by Dave
    I didn't really know how to phrase the title of my questions, so my apologies in advance. I read through parts of the MEF documentation to try to find the answer to my question, but couldn't find it. I'm using ImportMany to allow MEF to create multiple instances of a specific plugin. That plugin Imports several parts, and within calls to a specific instance, it wants these Imports to be singletons. However, what I don't want is for all instances of this plugin to use the same singleton. For example, let's say my application ImportManys Blender appliances. Every time I ask for one, I want a different Blender. However, each Blender Imports a ControlPanel. I want each Blender to have its own ControlPanel. To make things a little more interesting, each Blender can load BlendPrograms, which are also contained within their own assemblies, and MEF takes care of this loading. A BlendProgram might need to access the ControlPanel to get the speed, but I want to ensure that it is accessing the correct ControlPanel (i.e. the one that is associated with the Blender that is associated with the program!) This diagram might clear things up a little bit: As the note shows, I believe that the confusion could come from an inherently-poor design. The BlendProgram shouldn't touch the ControlPanel directly, and instead perhaps the BlendProgram should get the speed via the Blender, which will then delegate the request to its ControlPanel. If this is the case, then I assume the BlendProgram needs to have a reference to a specific Blender. In order to do this, is the right way to leverage MEF and use an ImportingConstructor for BlendProgram, i.e. [ImportingConstructor] public class BlendProgram : IBlendProgram { public BlendProgram( Blender blender) {} } And if this is the case, how do I know that MEF will use the intended Blender plugin?

    Read the article

  • Looking for detailed explanation of Hibernate UserType methods for mutable objects

    - by Tom
    I am creating a custom UserType class in Hibernate. The specific case is for an HL7v3 clinical document (I work in health IT). It is a mutable object and most of the documentation around the Hibernate UserType interface seems to center around immutable types. I want a better understanding of how and when the interface methods are used, specifically: assemble - why two parameters (one Serializable, one Object)? What is the use case for this method? disassemble - should I just implement this method to return a serializable form (e.g. String representation)? When and how is this method invoked? equals - is this for update? read? contention? dirty reads? What are the consequences of simply returning false in most cases? replace - I really don't understand where the three Object parameters come from, when this method is invoked, and what Hibernate expects to return, or how that return value is used. Any pointers would be appreciated. I've searched and read all I can find on the subject, but have not found much documentation at all explaining how these methods are used for mutable objects.

    Read the article

  • onTouchListener togglebutton, ignores first press?

    - by Paul
    I have a togglebutton that should run code when I press it down and more code when I let go. However the first time I press and let go nothing happens. Every other time it is fine, why is this? I can see the method only runs the first time when I let go of the button (it does not trigger any onTouch part of the method though), how can I get around this, and have it work for the first press? public void pushtotalk3(final View view) { ((ToggleButton) view).setChecked(true); ((ToggleButton) view).setChecked(false); view.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { //if more than one call, change this code int callId = 0; for (SipCallSession callInfo : callsInfo) { callId = callInfo.getCallId(); Log.e(TAG, "" + callInfo.getCallId()); } final int id = callId; switch (event.getAction()) { case MotionEvent.ACTION_DOWN: { //press ((ToggleButton) view).setBackgroundResource(R.drawable.btn_blue_glossy); ((ToggleButton) view).setChecked(true); OnDtmf(id, 17, 10); OnDtmf(id, 16, 9); return true; } case MotionEvent.ACTION_UP: { //release ((ToggleButton) view).setBackgroundResource(R.drawable.btn_lightblue_glossy); ((ToggleButton) view).setChecked(false); OnDtmf(id, 18, 11); OnDtmf(id, 18, 11); return true; } default: return false; } } }); } EDIT: the xml for the button: <ToggleButton android:id="@+id/PTT_button5" android:layout_width="0dp" android:layout_height="fill_parent" android:text="@string/ptt5" android:onClick="pushtotalk5" android:layout_weight="50" android:textOn="Push To Talk On" android:textOff="Push To Talk Off" android:background="@drawable/btn_lightblue_glossy" android:textColor="@android:color/white" android:textSize="15sp" /> EDIT: hardware problem, can't test solutions atm.

    Read the article

  • Dynamically change ViewPagerIndicator titles

    - by msal
    My current project uses some ListFragments to show rows of data. The rows get updated dynamically every some seconds. The amount of rows varies with every update and in every ListFragment. I would like to show the amount of rows to the user, and think that the perfect place for that would be next to the Fragment's title in the ViewPagerIndicator. I provided a sample image for better comprehension: Sadly I am pretty clueless how to achieve this. I tried the following: public class PagerAdapter extends FragmentPagerAdapter { private int numOne = 0; private int numTwo = 0; // ... @Override public CharSequence getPageTitle(int position) { switch (position) { case 0: return "List 1 (" + numOne + ")"; case 1: return "List 2 (" + numTwo + ")"; default: return ""; } public void setNumOne(int num) { this.numOne = num; } public void setNumTwo(int num) { this.numTwo = num; } } When I now call the setNumXXX() method, nothing happens, until I move between fragments, what seems to trigger the getPageTitle() to fire. My question is: How can I force an update of the title(s), everytime when the num value changes?

    Read the article

  • Problem with date_select when using :discard option. (Rails)

    - by MikeH
    I'm using a date_select with the option :discard_year => true If a user selects a date in the date select, and then he comes back and returns the select to the prompt values of Month and Day, Rails automatically sets the select values to January 1. I know this is the intended functionality if a month is selected and a day is left blank, but that's not the case here. In my example, the user sets both the month and day back to the prompt. By Rails forcing January 1, I'm getting bad results. I've tried every parameter available in the api. :default = nil, :include_blank = true. None of those change the behavior I'm describing. I've isolated the root of the problem, which is this: Because I'm discarding the :year parameter, when the user tries to return the month and day to the prompt values, Rails doesn't see an empty prompt select. It perhaps sees a year selected with empty month and day, which it then sets to January 1. This is the case because the :discard_year parameter does in fact set a date in the database, it just removes it from the view. How can I code around this problem?

    Read the article

  • Checking for empty arrays: count vs empty

    - by Dan McG
    This question on 'How to tell if a PHP array is empty' had me thinking of this question Is there a reason that count should be used instead of empty when determining if an array is empty or not? My personal thought would be if the 2 are equivalent for the case of empty arrays you should use empty because it gives a boolean answer to a boolean question. From the question linked above, it seems that count($var) == 0 is the popular method. To me, while technically correct, makes no sense. E.g. Q: $var, are you empty? A: 7. Hmmm... Is there a reason I should use count == 0 instead or just a matter of personal taste? As pointed out by others in comments for a now deleted answer, count will have performance impacts for large arrays because it will have to count all elements, whereas empty can stop as soon as it knows it isn't empty. So, if they give the same results in this case, but count is potentially inefficient, why would we ever use count($var) == 0?

    Read the article

  • hibernate c3p0 broken pipe

    - by raven_arkadon
    Hi, I'm using hibernate 3 with c3p0 for a program which constantly extracts data from some source and writes it to a database. Now the problem is, that the database might become unavailable for some reasons (in the simplest case: i simply shut it down). If anything is about to be written to the database there should not be any exception - the query should wait for all eternity until the database becomes available again. If I'm not mistaken this is one of the things the connection pool could do for me: if there is a problem with the db, just retry to connect - in the worst case for infinity. But instead i get a broken pipe exception, sometimes followed by connection refused and then the exception is passed to my own code, which shouldn't happen. Even if I catch the exception, how could i cleanly reinitialize hibernate again? (So far without c3p0 i simply built the session factory again, but i wouldn't be surprised if that could leak connections (or is it ok to do so?)). The database is Virtuoso open source edition. My hibernate.xml.cfg c3p0 config: <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property> <property name="hibernate.c3p0.breakAfterAcquireFailure">false</property> <property name="hibernate.c3p0.acquireRetryAttempts">-1</property> <property name="hibernate.c3p0.acquireRetryDelay">30000</property> <property name="hibernate.c3p0.automaticTestTable">my_test_table</property> <property name="hibernate.c3p0.initialPoolSize">3</property> <property name="hibernate.c3p0.minPoolSize">3</property> <property name="hibernate.c3p0.maxPoolSize">10</property> btw: The test table is created and i get tons of debug output- so it seems it actually reads the config.

    Read the article

  • Caching Authentication Data

    - by PartlyCloudy
    Hi, I'm currently implementing a REST web service using CouchDB and RESTlet. The RESTlet layer is mainly for authentication and some minor filtering of the JSON data served by CouchDB: Clients <= HTTP = [ RESTlet <= HTTP = CouchDB ] I'm using CouchDB also to store user login data, because I don't want to add an additional database server for that purpose. Thus, each request to my service causes two CouchDB requests conducted by RESTlet (auth data + "real" request). In order to keep the service as efficent as possible, I want to reduce the number of requests, in this case redundant requests for login data. My idea now is to provide a cache (i.e.LRU-Cache via LinkedHashMap) within my RESTlet application that caches login data, because HTTP caching will probabily not be enough. But how do I invalidate the cache data, once a user changes the password, for instance. Thanks to REST, the application might run on several servers in parallel, and I don't want to create a central instance just to cache login data. Currently, I save requested auth data in the cache and try to auth new requests by using them. If a authentication fails or there is now entry available, I'll dispatch a GET request to my CouchDB storage in order to obtain the actual auth data. So in a worst case, users that have changed their data will perhaps still be able to login with their old credentials. How can I deal with that? Or what is a good strategy to keep the cache(s) up-to-date in general? Thanks in advance.

    Read the article

  • highlight the text of the DOM range element,

    - by ganapati hegde
    I select some text on the html page(opened in firefox) using mouse,and using javascript functions, i create/get the rangeobject corresponding to the selected text. userSelection =window.getSelection(); var rangeObject = getRangeObject(userSelection); Now i want to highlight all the text which comes under the rangeobject.I am doing it like this, var span = document.createElement("span"); rangeObject.surroundContents(span); span.style.backgroundColor = "yellow"; Well,this works fine, only when the rangeobject(startpoint and endpoint) lies in the same textnode,then it highlights the corresponding text.Ex <p>In this case,the text selected will be highlighted properly, because the selected text lies under a single textnode</p> But if the rangeobject covers more than one textnode, then it is not working properlay, It highlights only the texts which lie in the first textnode,Ex <p><h3>In this case</h3>, only the text inside the header(h3) will be highlighted, not any text outside the header</p> Any idea how can i make, all the texts which comes under rangeobject,highlighted,independent of whether range lies in a single node or multiple node? Thanks....

    Read the article

  • How much effort do you have to put in to get gains from using SSE?

    - by John
    Case One Say you have a little class: class Point3D { private: float x,y,z; public: operator+=() ...etc }; Point3D &Point3D::operator+=(Point3D &other) { this->x += other.x; this->y += other.y; this->z += other.z; } A naive use of SSE would simply replace these function bodies with using a few intrinsics. But would we expect this to make much difference? MMX used to involve costly state cahnges IIRC, does SSE or are they just like other instructions? And even if there's no direct "use SSE" overhead, would moving the values into SSE registers and back out again really make it any faster? Case Two Instead, you're working with a less OO-based code base. Rather than an array/vector of Point3D objects, you simply have a big array of floats: float coordinateData[NUM_POINTS*3]; void add(int i,int j) //yes it's unsafe, no overlap check... example only { for (int x=0;x<3;++x) { coordinateData[i*3+x] += coordinateData[j*3+x]; } } What about use of SSE here? Any better? In conclusion Is trying to optimise single vector operations using SSE actually worthwhile, or is it really only valuable when doing bulk operations?

    Read the article

  • Cant run application (C#) through cmd

    - by user301639
    Hey, I cant execute application through cmd, when the application trying to read the argument which was sent to it (text file), it fails... when i'm truing to execute it through the IDE (vs2008), it works ok... that's what i did in the main method : static void Main(string[] args) { int choice = 0; if (args.Length == 0) choice = 1; else choice = 2; switch(choice) { case 1: { string[] text = Directory.GetFiles("allText"); Console.WriteLine(DateTime.Now.ToString()); foreach (string fileName in text) { string substring = fileName.Substring(8); ReadData_Logic rd_l = new ReadData_Logic(substring); rd_l.runThreadsAndDecrypt(); rd_l.printKey(substring.Substring(0, fileName.Length - 15).Insert(0, "encryptedKey\\") + "_result.txt"); } Console.WriteLine(DateTime.Now.ToString()); } break; case 2: { Console.WriteLine(DateTime.Now.ToString()); string fileName = args[0]; Console.WriteLine(fileName); **<--- for debug, here i do see the correct file name** ReadData_Logic rd_l = new ReadData_Logic(fileName); rd_l.runThreadsAndDecrypt(); rd_l.printKey(fileName + "_result.txt"); Console.WriteLine(DateTime.Now.ToString()); } break; } } what wrong with the code ? thanks

    Read the article

  • MongoDB in Go (golang) with mgo: How do I update a record, find out if update was successful and get the data in a single atomic operation?

    - by Sebastián Grignoli
    I am using mgo driver for MongoDB under Go. My application asks for a task (with just a record select in Mongo from a collection called "jobs") and then registers itself as an asignee to complete that task (an update to that same "job" record, setting itself as assignee). The program will be running on several machines, all talking to the same Mongo. When my program lists the available tasks and then picks one, other instances might have already obtained that assignment, and the current assignment would have failed. How can I get sure that the record I read and then update does or does not have a certain value (in this case, an assignee) at the time of being updated? I am trying to get one assignment, no matter wich one, so I think I should first select a pending task and try to assign it, keeping it just in the case the updating was successful. So, my query should be something like: "From all records on collection 'jobs', update just one that has asignee=null, setting my ID as the assignee. Then, give me that record so I could run the job." How could I express that with mgo driver for Go?

    Read the article

  • cast operator to base class within a thin wrapper derived class

    - by miked
    I have a derived class that's a very thin wrapper around a base class. Basically, I have a class that has two ways that it can be compared depending on how you interpret it so I created a new class that derives from the base class and only has new constructors (that just delegate to the base class) and a new operator==. What I'd like to do is overload the operator Base&() in the Derived class so in cases where I need to interpret it as the Base. For example: class Base { Base(stuff); Base(const Base& that); bool operator==(Base& rhs); //typical equality test }; class Derived : public Base { Derived(stuff) : Base(stuff) {}; Derived(const Base& that) : Base(that) {}; Derived(const Derived& that) : Base(that) {}; bool operator==(Derived& rhs); //special case equality test operator Base&() { return (Base&)*this; //Is this OK? It seems wrong to me. } }; If you want a simple example of what I'm trying to do, pretend I had a String class and String==String is the typical character by character comparison. But I created a new class CaseInsensitiveString that did a case insensitive compare on CaseInsensitiveString==CaseInsensitiveString but in all other cases just behaved like a String. it doesn't even have any new data members, just an overloaded operator==. (Please, don't tell me to use std::string, this is just an example!) Am I going about this right? Something seems fishy, but I can't put my finger on it.

    Read the article

  • private class calling a method from its outer class

    - by oxinabox.ucc.asn.au
    Ok, so I have a class for a "Advanced Data Structure" (in this case a kinda tree) SO I implimented a Iterator as a private class with in it. So the iterator needs to implement a remove function to remove the last retuirned element. now my ADT already impliments a remove function, and in this case there is very little (thinking about it, i think nothing) to be gain by implimenting a different remove function for the iterator. so how do I go about calling the remove from my ADT sketch of my struture: public class ADT { ... private class ADT_Iterator impliments java.util.Itorator{ ... public void remove(){ //where I want to call the ADT's remove function from } ... public void remove( Object paramFoo ) { ... } ... } So just calling remove(FooInstance) won't work (will it?) and this.remove(FooInstance) is the same thing. what do i call? (and changign the name of the ADT's remove function is not an option, as that AD T has to meet an Interace wich I am note at liberty to change) I could make both of them call a removeHelper functon, I guess...

    Read the article

  • Using collections/containers/catalogs in Domain Models

    - by devoured elysium
    Let's say I want to model a cinema. The cinema will have a couple of rooms(for example, 7), where the movies are being played. I wonder how should I design the domain model for this scenario. Should the Cinema class concept concept have a direct association with the 7 rooms? Should the Cinema class concept have an association with a catalog of the 7 rooms? Why? I am having some trouble understanding why in some places I see the first case and in some others I see something like the second case. If instead of rooms, I wanted to depict the relationship between Cinema and: Tickets to sell (today). Tickets already sold (today) Customers in the Cinema database The set of hours at which there are movies playing in a given room in the cinema. The set of places you can sit at in a room in the cinema. Should I use catalogs, should I connect them directly to the Cinema concept with a multiplicity of * in the target? Thanks

    Read the article

  • Distributing a bundle of files across an extranet

    - by John Zwinck
    I want to be able to distribute bundles of files, about 500 MB per bundle, to all machines on a corporate "extranet" (which is basically a few LANs connected using various private mechanisms, including leased lines and VPN). The total number of hosts is roughly 100, and the goal is to get a copy of the bundle from one host onto all the other hosts reliably, quickly, and efficiently. One important issue is that some hosts are grouped together on single fast LANs in which case the network I/O should be done once from one group to the next and then within each group between all the peers. This is as opposed to a strict central server system where multiple hosts might each fetch the same bundle over a slow link, rather than once via the slow link and then between each other quickly. A new bundle will be produced every few days, and occasionally old bundles will be deleted (but that problem can be solved separately). The machines in question happen to run recent Linuxes, but bonus points will go to solutions which are at least somewhat cross-platform (in which case the bundle might differ per platform but maybe the same mechanism can be used). That's pretty much it. I'm not opposed to writing some code to handle this, but it would be preferable if it were one of bash, Python, Ruby, Lua, C, or C++.

    Read the article

  • using switch in strings

    - by xtemer
    guys me trying to use switch in strings by first coverting string into char and then apply switch but still didnt done it....here is my code..help me out.. import javax.swing.*; import java.io.*; class HappyBirthday { public static void main(String[] args) throws IOException { String Month; char[] Months = Month.toCharArray(); BufferedReader dataIn= new BufferedReader(new InputStreamReader(System.in)); System.out.println("Please enter your month."); Month = JOptionPane.showInputDialog("enter month"); String month1={"January","feb"}; char[] month2 = month1.toCharArray(); // String s=month1.equals(Month); //System.out.print(month2Array[0]); switch (month2) { case 0: System.out.println("kool"); break; case 1: System.out.println("not kool"); break; default: }}} /** if (month1[1].equals(Month)) System.out.println("kool"); else if(month1[0].equals(Month)) System.out.println("kooooooooooooool"); else System.out.println("Big kooooool"); **/

    Read the article

  • Multiple elements with the same name with SimpleXML and Java

    - by LouieGeetoo
    I'm trying to use SimpleXML to parse an XML document (an ItemLookupResponse for a book from the Amazon Product Advertising API) which contains the following element: <ItemAttributes> <Author>Shane Conder</Author> <Author>Lauren Darcey</Author> <Manufacturer>Pearson Educacion</Manufacturer> <ProductGroup>Book</ProductGroup> <Title>Android Wireless Application Development: Barnes & Noble Special Edition</Title> </ItemAttributes> My problem is that I don't know how to deal with the multiple possible Author elements. Here's what I have right now for the corresponding POJO (Plain Old Java Object), keeping in mind that it's not handling the case of multiple Authors: @Element public class ItemAttributes { @Element public String Author; @Element public String Manufacturer; @Element public String Title; } (I don't care about the ProductGroup, so it's not in the class -- I'm just setting SimpleXML's strict mode to off to allow for that.) I couldn't find an example in the documentation that corresponded with such a case. Using an ElementList with (inline=true) seemed along the right lines, but I didn't see how to do it for String (as opposed to a separate Author class, which I have no need for and don't see how it would even work). Here's a similar question and answer, but for PHP: php - simpleXML how to access a specific element with the same name as others? I don't know what the Java equivalent would be to the accepted answer. Thanks in advance.

    Read the article

  • Is my method for avoiding dynamic_cast<> faster than dynamic_cast<> itself ?

    - by ereOn
    Hi, I was answering a question a few minutes ago and it raised to me another one: In one of my projects, I do some network message parsing. The messages are in the form of: [1 byte message type][2 bytes payload length][x bytes payload] The format and content of the payload are determined by the message type. I have a class hierarchy, based on a common class Message. To instanciate my messages, i have a static parsing method which gives back a Message* depending on the message type byte. Something like: Message* parse(const char* frame) { // This is sample code, in real life I obviously check that the buffer // is not NULL, and the size, and so on. switch(frame[0]) { case 0x01: return new FooMessage(); case 0x02: return new BarMessage(); } // Throw an exception here because the mesage type is unknown. } I sometimes need to access the methods of the subclasses. Since my network message handling must be fast, I decived to avoid dynamic_cast<> and I added a method to the base Message class that gives back the message type. Depending on this return value, I use a static_cast<> to the right child type instead. I did this mainly because I was told once that dynamic_cast<> was slow. However, I don't know exactly what it really does and how slow it is, thus, my method might be as just as slow (or slower) but far more complicated. What do you guys think of this design ? Is it common ? Is it really faster than using dynamic_cast<> ? Any detailed explanation of what happen under the hood when one use dynamic_cast<> is welcome !

    Read the article

  • Should i enforce realloc check if the new block size is smaller than the initial ?

    - by nomemory
    Can realloc fail in this case ? int *a = NULL; a = calloc(100, sizeof(*a)); printf("1.ptr: %d \n", a); a = realloc(a, 50 * sizeof(*a)); printf("2.ptr: %d \n", a); if(a == NULL){ printf("Is it possible?"); } return (0); } The output in my case is: 1.ptr: 4072560 2.ptr: 4072560 So 'a' points to the same adress. So should i enforce realloc check ? Later edit: Using MinGW compiler under Windows XP. Is the behaviour similar with gcc on Linux ? Later edit 2: Is it OK to check this way ? int *a = NULL, *b = NULL; a = calloc(100, sizeof(*a)); b = realloc(a, 50 * sizeof(*a)); if(b == NULL){ return a; } a = b; return a;

    Read the article

  • what does this attempted trojan horse code do?

    - by bstullkid
    It looks like this just sends a ping, but whats the point of that when you can just use ping? /* WARNING: this is someone's attempt at writing a malware trojan. Do not compile and *definitely* don't install. I added an exit as the first line to avoid mishaps - msw */ int main (int argc, char *argv[]) { exit(1); unsigned int pid = 0; char buffer[2]; char *args[] = { "/bin/ping", "-c", "5", NULL, NULL }; if (argc != 2) return 0; args[3] = strdup(argv[1]); for (;;) { gets(buffer); /* FTW */ if (buffer[0] == 0x6e) break; switch (pid = fork()) { case -1: printf("Error Forking\n"); exit(255); case 0: execvp(args[0], args); exit(1); default: break; } } return 255; }

    Read the article

  • Binary Search Tree for specific intent

    - by Luís Guilherme
    We all know there are plenty of self-balancing binary search trees (BST), being the most famous the Red-Black and the AVL. It might be useful to take a look at AA-trees and scapegoat trees too. I want to do deletions insertions and searches, like any other BST. However, it will be common to delete all values in a given range, or deleting whole subtrees. So: I want to insert, search, remove values in O(log n) (balanced tree). I would like to delete a subtree, keeping the whole tree balanced, in O(log n) (worst-case or amortized) It might be useful to delete several values in a row, before balancing the tree I will most often insert 2 values at once, however this is not a rule (just a tip in case there is a tree data structure that takes this into account) Is there a variant of AVL or RB that helps me on this? Scapegoat-trees look more like this, but would also need some changes, anyone who has got experience on them can share some thougts? More precisely, which balancing procedure and/or removal procedure would help me keep this actions time-efficient?

    Read the article

< Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >