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  • C++ strongly typed typedef

    - by Kian
    I've been trying to think of a way of declaring strongly typed typedefs, to catch a certain class of bugs in the compilation stage. It's often the case that I'll typedef an int into several types of ids, or a vector to position or velocity: typedef int EntityID; typedef int ModelID; typedef Vector3 Position; typedef Vector3 Velocity; This can make the intent of code more clear, but after a long night of coding one might make silly mistakes like comparing different kinds of ids, or adding a position to a velocity perhaps. EntityID eID; ModelID mID; if ( eID == mID ) // <- Compiler sees nothing wrong { /*bug*/ } Position p; Velocity v; Position newP = p + v; // bug, meant p + v*s but compiler sees nothing wrong Unfortunately, suggestions I've found for strongly typed typedefs include using boost, which at least for me isn't a possibility (I do have c++11 at least). So after a bit of thinking, I came upon this idea, and wanted to run it by someone. First, you declare the base type as a template. The template parameter isn't used for anything in the definition, however: template < typename T > class IDType { unsigned int m_id; public: IDType( unsigned int const& i_id ): m_id {i_id} {}; friend bool operator==<T>( IDType<T> const& i_lhs, IDType<T> const& i_rhs ); }; Friend functions actually need to be forward declared before the class definition, which requires a forward declaration of the template class. We then define all the members for the base type, just remembering that it's a template class. Finally, when we want to use it, we typedef it as: class EntityT; typedef IDType<EntityT> EntityID; class ModelT; typedef IDType<ModelT> ModelID; The types are now entirely separate. Functions that take an EntityID will throw a compiler error if you try to feed them a ModelID instead, for example. Aside from having to declare the base types as templates, with the issues that entails, it's also fairly compact. I was hoping anyone had comments or critiques about this idea? One issue that came to mind while writing this, in the case of positions and velocities for example, would be that I can't convert between types as freely as before. Where before multiplying a vector by a scalar would give another vector, so I could do: typedef float Time; typedef Vector3 Position; typedef Vector3 Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; With my strongly typed typedef I'd have to tell the compiler that multypling a Velocity by a Time results in a Position. class TimeT; typedef Float<TimeT> Time; class PositionT; typedef Vector3<PositionT> Position; class VelocityT; typedef Vector3<VelocityT> Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; // Compiler error To solve this, I think I'd have to specialize every conversion explicitly, which can be kind of a bother. On the other hand, this limitation can help prevent other kinds of errors (say, multiplying a Velocity by a Distance, perhaps, which wouldn't make sense in this domain). So I'm torn, and wondering if people have any opinions on my original issue, or my approach to solving it.

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  • Integer type or not [closed]

    - by kira
    I am writing a program (in cpp) to check the primality of a given number The point where i am struck is , I need to check in between the program wether the value i obtained upon some arithmetic operations on the input is an integer or not i.e lets say input is 'a' I want to know how to check if 'b' is integer or not (FYI, b=(a+1)/6 ) My attempt for this : int main() { using std::cin; using std::cout; int b,c; int a; cout<<"enter the number"; cin>>a; b=(a+1)/6; c=(a-1)/6; if (b is an integer) cout << "The given number is prime"; else if (c is an integer) cin << "The given number is prime!"; else cout<<"The number is not prime"; return 0; }

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  • SQL Server Data Type Precedence

    I am executing a simple query/stored procedure from my application against a large table and it's taking a long time to execute. The column I'm using in my WHERE clause is indexed and it's very selective. The search column is not wrapped in a function so that's not the issue. What could be going wrong? Schedule Azure backupsRed Gate’s Cloud Services makes it simple to create and schedule backups of your SQL Azure databases to Azure blob storage or Amazon S3. Try it for free today.

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  • Data Compare is Finally Back in VS 2012

    - by Aligned
    Originally posted on: http://geekswithblogs.net/Aligned/archive/2013/07/01/data-compare-is-finally-back-in-vs-2012.aspxI’ve been missing the data compare tool this since moving from VS 2010. I’ve install the VS 2013 v3 update and then the SQL Server Data Tools - June 2013 update. I don’t think v3 is required, but it’s a good upgrade to do anyways. http://blogs.msdn.com/b/ssdt/archive/2013/06/24/announcing-sql-server-data-tools-june-2013.aspx

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  • Live search/filter as you type in client approach

    - by Pinoniq
    As an exercise for myself to practice my JavaScript "skills" I'm trying to write a client-side filter. It should be able to filter "content blocks" as the user types. By "content block", I mean a list of DomElements that each contain at least one text node - it is possible that they contain more, and even a different amount of text nodes, nested inside other nodes, etc. I've thought of 2 approaches: On page initialization, scan all nodes and store all the text in some kind of Map or a tree. Simply iterate over every item and check whether it has the string to search/filter for. One could add performance here by caching, only filtering the current remaining items if text is added, etc. Obviously, if the number of nodes is really big, option 1 will take a while to build the 'index' but it will perform faster once it is built. Option 2 however will be available right on page load since no initialization is performed. But of course it will take longer to search. So my question is: what is the best approach here? And how would one implement 'caching' and/or 'index'?

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  • ????????SQL Developer?Data Modeler?????????????

    - by Yusuke.Yamamoto
    ????? ??:2010/05/18 ??:?????? Oracle ?GUI?????????···??????????????????SQL Developer ? Data Modeler ???????GUI???????????????????????????SQL Developer ? Data Modeler ?????????????????? ????Oracle SQL Developer Data Modeler ??Oracle SQL Developer Data Modeler ????Oracle SQL Developer ???Oracle SQL Developer ???????? ????????? ????????????????? http://www.oracle.com/technology/global/jp/ondemand/otn-seminar/pdf/100518_sqldeveloper_evening.pdf

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  • ??????????????????????????????????????????????????Oracle Database 11g Enterprise Edition??????Oracle Data Guard?

    - by Yusuke.Yamamoto
    ????? ??:2011/05/25 ??:???? ??3??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? Oracle Database 11g Enterprise Edition ?????????????????????????·???????????Oracle Data Guard????????????????? Oracle Data Guard ??????????????????????????????? ????????????????????????? Oracle Data Guard???????"???"????????????????????????????????????WAN????????????????????????Oracle Data Guard ?????? ????????? ????????????????? http://oracletech.jp/products/pickup/000298.html

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  • Object of type 'customObject' cannot be converted to type 'customObject'.

    - by Phani Kumar PV
    i am receiving the follwing error when i am invoking a custom object "Object of type 'customObject' cannot be converted to type 'customObject'." Following is the scenario when i am getting the error i am invoking a method in a dll dynamically. Load an assembly CreateInstance.... calling MethodInfo.Invoke() passing int, string as a parameter for my method is working fine = No exceptions are thrown. But if I try and pass a one of my own custom class objects as a parameter, then I get an ArgumentException exception, and it is not either an ArgumentOutOfRangeException or ArgumentNullException. "Object of type 'customObject' cannot be converted to type 'customObject'." I am doing this in a web application. The class file containing the method is in a different proj . also the custom object is a sepearte class in the same file. there is no such thing called a static aseembly in my code. I am trying to invoke a webmethod dynamically. this webmethod is having the customObject type as an input parameter. So when i invoke the webmethod i am dynamically creating the proxy assembly and all. From the same assembly i am trying to create an instance of the cusotm object assinging the values to its properties and then passing this object as a parameter and invoking the method. everything is dynamic and nothing is created static.. :( add reference is not used. Following is a sample code i tried to create it public static object CallWebService(string webServiceAsmxUrl, string serviceName, string methodName, object[] args) { System.Net.WebClient client = new System.Net.WebClient(); //-Connect To the web service using (System.IO.Stream stream = client.OpenRead(webServiceAsmxUrl + "?wsdl")) { //--Now read the WSDL file describing a service. ServiceDescription description = ServiceDescription.Read(stream); ///// LOAD THE DOM ///////// //--Initialize a service description importer. ServiceDescriptionImporter importer = new ServiceDescriptionImporter(); importer.ProtocolName = "Soap12"; // Use SOAP 1.2. importer.AddServiceDescription(description, null, null); //--Generate a proxy client. importer.Style = ServiceDescriptionImportStyle.Client; //--Generate properties to represent primitive values. importer.CodeGenerationOptions = System.Xml.Serialization.CodeGenerationOptions.GenerateProperties; //--Initialize a Code-DOM tree into which we will import the service. CodeNamespace nmspace = new CodeNamespace(); CodeCompileUnit unit1 = new CodeCompileUnit(); unit1.Namespaces.Add(nmspace); //--Import the service into the Code-DOM tree. This creates proxy code //--that uses the service. ServiceDescriptionImportWarnings warning = importer.Import(nmspace, unit1); if (warning == 0) //--If zero then we are good to go { //--Generate the proxy code CodeDomProvider provider1 = CodeDomProvider.CreateProvider("CSharp"); //--Compile the assembly proxy with the appropriate references string[] assemblyReferences = new string[5] { "System.dll", "System.Web.Services.dll", "System.Web.dll", "System.Xml.dll", "System.Data.dll" }; CompilerParameters parms = new CompilerParameters(assemblyReferences); CompilerResults results = provider1.CompileAssemblyFromDom(parms, unit1); //-Check For Errors if (results.Errors.Count > 0) { StringBuilder sb = new StringBuilder(); foreach (CompilerError oops in results.Errors) { sb.AppendLine("========Compiler error============"); sb.AppendLine(oops.ErrorText); } throw new System.ApplicationException("Compile Error Occured calling webservice. " + sb.ToString()); } //--Finally, Invoke the web service method Type foundType = null; Type[] types = results.CompiledAssembly.GetTypes(); foreach (Type type in types) { if (type.BaseType == typeof(System.Web.Services.Protocols.SoapHttpClientProtocol)) { Console.WriteLine(type.ToString()); foundType = type; } } object wsvcClass = results.CompiledAssembly.CreateInstance(foundType.ToString()); MethodInfo mi = wsvcClass.GetType().GetMethod(methodName); return mi.Invoke(wsvcClass, args); } else { return null; } } } I cant find anything static being done by me. any help is greatly appreciated. Regards, Phani Kumar PV

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  • "type" Command Not Working As Expected on Git Bash

    - by trysis
    The type command, in Linux, returns the location, on the filesystem, of the given file, if it is in the current folder or the $PATH. This functionality is also available through Windows with the Git Bash command line program. The command also returns a file's location given the file without its extension (.exe, .vbs, etc.) However, I have run into what seems like a strange corner case where the file exists on the $PATH but doesn't get returned using the command. I am thinking of buying a new computer soon, so I looked up the method of transferring the license key from one computer to another, in preparation for actually doing this. The method I found mentioned the files slmgr.vbs and slui.exe, both of which reside in the C:/Windows\System32 folder, which is in my $PATH, as usual for a Windows computer. However, these two files aren't showing up when I use the type command. Also, neither gets executed when I call the files as commands without their extensions in Git Bash, and only slmgr.vbs gets executed when I call them with the extensions. Finally, slmgr.vbs is shown when listing the folder's contents in Git Bash, as well, but slui.exe isn't. I thought this might have to do with permissions, and, indeed, both files have very restrictive permissions, as you can see in the pictures below, but they both have the same permissions, which wouldn't explain why one gets executed and the other doesn't when called directly, nor why one file is listed on command line but the other isn't. C:\Windows\System32 folder, proving the files exist: File permissions for the Users and Administrators groups for the two files (they are identical): And the folder: type command and its output in Git Bash for the 2 files, plus listing the files in the folder (using grep to filter as the folder is huge), as well as listing part of the $PATH (keep in mind, for all these, that Git Bash changes the paths as they are displayed): Sean@MYPC ~ $ type -a slmgr sh.exe": type: slmgr: not found Sean@MYPC ~ $ type -a slmgr.vbs sh.exe": type: slmgr.vbs: not found Sean@MYPC ~ $ type -a slui sh.exe": type: slui: not found Sean@MYPC ~ $ type -a slui.exe sh.exe": type: slui.exe: not found Sean@MYPC ~ $ slmgr sh.exe": slmgr: command not found Sean@MYPC ~ $ slmgr.vbs /c/WINDOWS/system32/slmgr.vbs: line 2: syntax error near unexpected token `(' /c/WINDOWS/system32/slmgr.vbs: line 2: `' Copyright (c) Microsoft Corporation. A ll rights reserved.' Sean@MYPC ~ $ slui sh.exe": slui: command not found Sean@MYPC ~ $ slui.exe sh.exe": slui.exe: command not found Sean@MYPC ~ $ ls /c/Windows/System32/slui.exe /c/Windows/System32/slmgr.vbs ls: /c/Windows/System32/slui.exe: No such file or directory /c/Windows/System32/slmgr.vbs Sean@MYPC ~ $ echo $PATH /c/Users/Sean/bin:.:/usr/local/bin:/mingw/bin:/bin:/cmd:/c/Python33/:/c/Program Files (x86)/Intel/iCLS Client/:/c/Program Files/Intel/iCLS Client/:/c/WINDOWS/sy stem32:/c/WINDOWS:/c/WINDOWS/System32/Wbem:/c/WINDOWS/System32/WindowsPowerShell /v1.0/:/c/Program Files/Intel/Intel(R) Management Engine Components/DAL:/c/Progr am Files/Intel/Intel(R) Management Engine Components/IPT:/c/Program Files (x86)/ Intel/Intel(R) Management Engine Components/DAL:/c/Program Files (x86)/Intel/Int el(R) Management Engine Components/IPT:/c/Program Files/Intel/WiFi/bin/:/c/Progr am Files/Common Files/Intel/WirelessCommon/:/c/strawberry/c/bin:/c/strawberry/pe rl/site/bin:/c/strawberry/perl/bin:/c/Program Files (x86)/Microsoft ASP.NET/ASP. NET Web Pages/v1.0/:/c/Program Files/Microsoft SQL Server/110/Tools/Binn/:/c/Pro gram Files (x86)/Microsoft SQL Server/90/Tools/binn/:/c/Program Files (x86)/Open AFS/Common:/c/HashiCorp/Vagrant/bin:/c/Program Files (x86)/Windows Kits/8.1/Wind ows Performance Toolkit/:/c/Program Files/nodejs/:/c/Program Files (x86)/Git/cmd :/c/Program Files (x86)/Git/bin:/c/Program Files/Microsoft/Web Platform Installe r/:/c/Ruby200-x64/bin:/c/Users/Sean/AppData/Local/Box/Box Edit/:/c/Program Files (x86)/SSH Communications Security/SSH Secure Shell:/c/Users/Sean/Documents/Lisp :/c/Program Files/GCL-2.6.1/lib/gcl-2.6.1/unixport:/c/Chocolatey/bin:/c/Users/Se an/AppData/Roaming/npm:/c/wamp/bin/mysql/mysql5.6.12/bin:/c/Program Files/Oracle /VirtualBox:/c/Program Files/Java/jdk1.7.0_51/bin:/c/Program Files/Node-Growl:/c /chocolatey/bin:/c/Program Files/eclipse:/c/MongoDB/bin:/c/Program Files/7-Zip:/ c/Program Files (x86)/Google/Chrome/Application:/c/Program Files (x86)/LibreOffi ce 4/program:/c/Program Files (x86)/OpenOffice 4/program What's happening? Why aren't these files listed with the type command? Is this issue because of weird Windows permissions, or something even weirder? If permissions, why do they seem to have the same permissions, yet both are not handled in the same way?

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  • Java inheritance question

    - by Milos
    I have an abstract class Airplane, and two classes PassengerAirplane and CargoAirplane, which extend class Airplane. I also have an interface Measurable, and two classes that implement it - People and Containers. So, Airplane can do many things on its own, and there is a method which allows measurable things to be added to the airplane (called addAMeasurableThing). The only difference between PassengerAirplane/CargoAirplane and just an Airplane is that addAMeasurableThing should only accept People / Containers, and not any kind Measurable things. How do I implement this? I tried doing: Airplane class: public abstract Airplane addAMeasurableThing (Measurable m, int position); PassengerAirplane class: public Airplane addAMeasurableThing (Measurable m, int position) { if (m instanceof People)... CargoAirplane class: public Airplane addAMeasurableThing (Measurable m, int position) { if (m instanceof Containers)... But when I was debugging it, I've noticed that addAMeasurableThing in the CargoAirplane class never gets called, because both methods have the same signature. So how can the appropriate PassengerAirplane/CargoAirplane's addAMeasurableThing be called, depending on the type of Measurable thing that is being passed on? Thanks!

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  • Problems Allocating Objects of Derived Class Where Base Class has Abstract Virtual Functions

    - by user1743901
    I am trying to get this Zombie/Human agent based simulation running, but I am having problems with these derived classes (Human and Zombie) who have parent class "Creature". I have 3 virtual functions declared in "Creature" and all three of these are re-declared AND DEFINED in both "Human" and "Zombie". But for some reason when I have my program call "new" to allocate memory for objects of type Human or Zombie, it complains about the virtual functions being abstract. Here's the code: definitions.h #ifndef definitions_h #define definitions_h class Creature; class Item; class Coords; class Grid { public: Creature*** cboard; Item*** iboard; int WIDTH; int HEIGHT; Grid(int WIDTHVALUE, int HEIGHTVALUE); void FillGrid(); //initializes grid object with humans and zombies void Refresh(); //calls Creature::Die(),Move(),Attack(),Breed() on every square void UpdateBuffer(char** buffer); bool isEmpty(int startx, int starty, int dir); char CreatureType(int xcoord, int ycoord); char CreatureType(int startx, int starty, int dir); }; class Random { public: int* rptr; void Print(); Random(int MIN, int MAX, int LEN); ~Random(); private: bool alreadyused(int checkthis, int len, int* rptr); bool isClean(); int len; }; class Coords { public: int x; int y; int MaxX; int MaxY; Coords() {x=0; y=0; MaxX=0; MaxY=0;} Coords(int X, int Y, int WIDTH, int HEIGHT) {x=X; y=Y; MaxX=WIDTH; MaxY=HEIGHT; } void MoveRight(); void MoveLeft(); void MoveUp(); void MoveDown(); void MoveUpRight(); void MoveUpLeft(); void MoveDownRight(); void MoveDownLeft(); void MoveDir(int dir); void setx(int X) {x=X;} void sety(int Y) {y=Y;} }; class Creature { public: bool alive; Coords Location; char displayletter; Creature() {Location.x=0; Location.y=0;} Creature(int i, int j) {Location.setx(i); Location.sety(j);} virtual void Attack() =0; virtual void AttackCreature(Grid G, int attackdirection) =0; virtual void Breed() =0; void Die(); void Move(Grid G); int DecideSquare(Grid G); void MoveTo(Grid G, int dir); }; class Human : public Creature { public: bool armed; //if armed, chances of winning fight increased for next fight bool vaccinated; //if vaccinated, no chance of getting infected int bitecount; //if a human is bitten, bite count is set to a random number int breedcount; //if a human goes x steps without combat, will breed if next to a human int starvecount; //if a human does not eat in x steps, will die Human() {displayletter='H';} Human(int i, int j) {displayletter='H';} void Attack(Grid G); void AttackCreature(Grid G, int attackdirection); void Breed(Grid G); //will breed after x steps and next to human int DecideAttack(Grid G); }; class Zombie : public Creature { public: Zombie() {displayletter='Z';} Zombie(int i, int j) {displayletter='Z';} void Attack(Grid G); void AttackCreature(Grid G, int attackdirection); void Breed() {} //does nothing int DecideAttack(Grid G); void AttackCreature(Grid G, int attackdirection); }; class Item { }; #endif definitions.cpp #include <cstdlib> #include "definitions.h" Random::Random(int MIN, int MAX, int LEN) //constructor { len=LEN; rptr=new int[LEN]; //allocate array of given length for (int i=0; i<LEN; i++) { int random; do { random = rand() % (MAX-MIN+1) + MIN; } while (alreadyused(random,LEN,rptr)); rptr[i]=random; } } bool Random::alreadyused(int checkthis, int len, int* rptr) { for (int i=0; i<len; i++) { if (rptr[i]==checkthis) return 1; } return 0; } Random::~Random() { delete rptr; } Grid::Grid(int WIDTHVALUE, int HEIGHTVALUE) { WIDTH = WIDTHVALUE; HEIGHT = HEIGHTVALUE; //builds 2d array of creature pointers cboard = new Creature**[WIDTH]; for(int i=0; i<WIDTH; i++) { cboard[i] = new Creature*[HEIGHT]; } //builds 2d array of item pointers iboard = new Item**[WIDTH]; for (int i=0; i<WIDTH; i++) { iboard[i] = new Item*[HEIGHT]; } } void Grid::FillGrid() { /* For each creature pointer in grid, randomly selects whether to initalize as zombie, human, or empty square. This methodology can be changed to initialize different creature types with different probabilities */ int random; for (int i=0; i<WIDTH; i++) { for (int j=0; j<HEIGHT; j++) { Random X(1,100,1); //create a single random integer from [1,100] at X.rptr random=*(X.rptr); if (random < 20) cboard[i][j] = new Human(i,j); else if (random < 40) cboard[i][j] = new Zombie(i,j); else cboard[i][j] = NULL; } } //at this point every creature pointer should be pointing to either //a zombie, human, or NULL with varying probabilities } void Grid::UpdateBuffer(char** buffer) { for (int i=0; i<WIDTH; i++) { for (int j=0; j<HEIGHT; j++) { if (cboard[i][j]) buffer[i][j]=cboard[i][j]->displayletter; else buffer[i][j]=' '; } } } bool Grid::isEmpty(int startx, int starty, int dir) { Coords StartLocation(startx,starty,WIDTH,HEIGHT); switch(dir) { case 1: StartLocation.MoveUp(); if (cboard[StartLocation.x][StartLocation.y]) return 0; case 2: StartLocation.MoveUpRight(); if (cboard[StartLocation.x][StartLocation.y]) return 0; case 3: StartLocation.MoveRight(); if (cboard[StartLocation.x][StartLocation.y]) return 0; case 4: StartLocation.MoveDownRight(); if (cboard[StartLocation.x][StartLocation.y]) return 0; case 5: StartLocation.MoveDown(); if (cboard[StartLocation.x][StartLocation.y]) return 0; case 6: StartLocation.MoveDownLeft(); if (cboard[StartLocation.x][StartLocation.y]) return 0; case 7: StartLocation.MoveLeft(); if (cboard[StartLocation.x][StartLocation.y]) return 0; case 8: StartLocation.MoveUpLeft(); if (cboard[StartLocation.x][StartLocation.y]) return 0; } return 1; } char Grid::CreatureType(int xcoord, int ycoord) { if (cboard[xcoord][ycoord]) //if there is a creature at location xcoord,ycoord return (cboard[xcoord][ycoord]->displayletter); else //if pointer at location xcoord,ycoord is null, return null char return '\0'; } char Grid::CreatureType(int startx, int starty, int dir) { Coords StartLocation(startx,starty,WIDTH,HEIGHT); switch(dir) { case 1: StartLocation.MoveUp(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); case 2: StartLocation.MoveUpRight(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); case 3: StartLocation.MoveRight(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); case 4: StartLocation.MoveDownRight(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); case 5: StartLocation.MoveDown(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); case 6: StartLocation.MoveDownLeft(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); case 7: StartLocation.MoveLeft(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); case 8: StartLocation.MoveUpLeft(); if (cboard[StartLocation.x][StartLocation.y]) return (cboard[StartLocation.x][StartLocation.y]->displayletter); } //if function hasn't returned by now, square being looked at is pointer to null return '\0'; //return null char } void Coords::MoveRight() {(x==MaxX)? (x=0):(x++);} void Coords::MoveLeft() {(x==0)? (x=MaxX):(x--);} void Coords::MoveUp() {(y==0)? (y=MaxY):(y--);} void Coords::MoveDown() {(y==MaxY)? (y=0):(y++);} void Coords::MoveUpRight() {MoveUp(); MoveRight();} void Coords::MoveUpLeft() {MoveUp(); MoveLeft();} void Coords::MoveDownRight() {MoveDown(); MoveRight();} void Coords::MoveDownLeft() {MoveDown(); MoveLeft();} void Coords::MoveDir(int dir) { switch(dir) { case 1: MoveUp(); break; case 2: MoveUpRight(); break; case 3: MoveRight(); break; case 4: MoveDownRight(); break; case 5: MoveDown(); break; case 6: MoveDownLeft(); break; case 7: MoveLeft(); break; case 8: MoveUpLeft(); break; case 0: break; } } void Creature::Move(Grid G) { int movedir=DecideSquare(G); MoveTo(G,movedir); } int Creature::DecideSquare(Grid G) { Random X(1,8,8); //X.rptr now points to 8 unique random integers from [1,8] for (int i=0; i<8; i++) { int dir=X.rptr[i]; if (G.isEmpty(Location.x,Location.y,dir)) return dir; } return 0; } void Creature::MoveTo(Grid G, int dir) { Coords OldLocation=Location; Location.MoveDir(dir); G.cboard[Location.x][Location.y]=this; //point new location to this creature G.cboard[OldLocation.x][OldLocation.y]=NULL; //point old location to NULL } void Creature::Die() { if (!alive) { delete this; this=NULL; } } void Human::Breed(Grid G) { if (!breedcount) { Coords BreedLocation=Location; Random X(1,8,8); for (int i=0; i<8; i++) { BreedLocation.MoveDir(X.rptr[i]); if (!G.cboard[BreedLocation.x][BreedLocation.y]) { G.cboard[BreedLocation.x][BreedLocation.y])=new Human(BreedLocation.x,BreedLocation.y); return; } } } } int Human::DecideAttack(Grid G) { Coords AttackLocation=Location; Random X(1,8,8); int attackdir; for (int i=0; i<8; i++) { attackdir=X.rptr[i]; switch(G.CreatureType(Location.x,Location.y,attackdir)) { case 'H': break; case 'Z': return attackdir; case '\0': break; default: break; } } return 0; //no zombies! } int AttackRoll(int para1, int para2) { //outcome 1: Zombie wins, human dies //outcome 2: Human wins, zombie dies //outcome 3: Human wins, zombie dies, but human is bitten Random X(1,100,1); int roll= *(X.rptr); if (roll < para1) return 1; else if (roll < para2) return 2; else return 3; } void Human::AttackCreature(Grid G, int attackdirection) { Coords AttackLocation=Location; AttackLocation.MoveDir(attackdirection); int para1=33; int para2=33; if (vaccinated) para2=101; //makes attackroll > para 2 impossible, never gets infected if (armed) para1-=16; //reduces chance of zombie winning fight int roll=AttackRoll(para1,para2); //outcome 1: Zombie wins, human dies //outcome 2: Human wins, zombie dies //outcome 3: Human wins, zombie dies, but human is bitten switch(roll) { case 1: alive=0; //human (this) dies return; case 2: G.cboard[AttackLocation.x][AttackLocation.y]->alive=0; return; //zombie dies case 3: G.cboard[AttackLocation.x][AttackLocation.y]->alive=0; //zombie dies Random X(3,7,1); //human is bitten bitecount=*(X.rptr); return; } } int Zombie::DecideAttack(Grid G) { Coords AttackLocation=Location; Random X(1,8,8); int attackdir; for (int i=0; i<8; i++) { attackdir=X.rptr[i]; switch(G.CreatureType(Location.x,Location.y,attackdir)) { case 'H': return attackdir; case 'Z': break; case '\0': break; default: break; } } return 0; //no zombies! } void Zombie::AttackCreature(Grid G, int attackdirection) { int reversedirection; if (attackdirection < 9 && attackdirection>0) { (attackdirection<5)? (reversedirection=attackdirection+4):(reversedirection=attackdirection-4); } else reversedirection=0; //this should never happen //when a zombie attacks a human, the Human::AttackZombie() function is called //in the "reverse" direction, utilizing that function that has already been written Coords ZombieLocation=Location; Coords HumanLocation=Location; HumanLocation.MoveDir(attackdirection); if (G.cboard[HumanLocation.x][HumanLocation.y]) //if there is a human there, which there should be G.cboard[HumanLocation.x][HumanLocation.y]->AttackCreature(G,reversedirection); } void Zombie::Attack(Grid G) { int attackdirection=DecideAttack(G); AttackCreature(G,attackdirection); } main.cpp #include <cstdlib> #include <iostream> #include "definitions.h" using namespace std; int main(int argc, char *argv[]) { Grid G(500,500); system("PAUSE"); return EXIT_SUCCESS; }

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  • c# - what approach can I use to extend a group of classes that include implemented methods? (see des

    - by Greg
    Hi, I want to create an extendible package I am writing that has Topology, Node & Relationship classes. The idea is these base classes would have the various methods in them necessary to base graph traversal methods etc. I would then like to be able to reuse this by extending the package. For example the base requirements might see Relationship with a parentNode & childNode. Topology would have a List of Nodes and List of Relationships. Topology would have methods like FindChildren(int depth). Then the usage would be to extend these such that additional attributes for Node and Relationships could be added etc. QUESTION - What would be the best approach to package & expose the base level classes/methods? (it's kind of like a custom collection but with multiple facets). Would the following concepts come into play: Interfaces - would this be a good idea to have ITopology, INode etc, or is this not required as the user would extend these classes anyway? Abstract Classes - would the base classes be abstract classes Custom Generic Collection - would some approach using this concept assist (but how would this work if there are the 3 different classes) thanks

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  • How can this Ambient Context become null?

    - by Mark Seemann
    Can anyone help me explain how TimeProvider.Current can become null in the following class? public abstract class TimeProvider { private static TimeProvider current = DefaultTimeProvider.Instance; public static TimeProvider Current { get { return TimeProvider.current; } set { if (value == null) { throw new ArgumentNullException("value"); } TimeProvider.current = value; } } public abstract DateTime UtcNow { get; } public static void ResetToDefault() { TimeProvider.current = DefaultTimeProvider.Instance; } } Observations All unit tests that directly reference TimeProvider also invokes ResetToDefault() in their Fixture Teardown. There is no multithreaded code involved. Once in a while, one of the unit tests fail because TimeProvider.Current is null (NullReferenceException is thrown). This only happens when I run the entire suite, but not when I just run a single unit test, suggesting to me that there is some subtle test interdependence going on. It happens approximately once every five or six test runs. When a failure occurs, it seems to be occuring in the first executed tests that involves TimeProvider.Current. More than one test can fail, but only one fails in a given test run. FWIW, here's the DefaultTimeProvider class as well: public class DefaultTimeProvider : TimeProvider { private readonly static DefaultTimeProvider instance = new DefaultTimeProvider(); private DefaultTimeProvider() { } public override DateTime UtcNow { get { return DateTime.UtcNow; } } public static DefaultTimeProvider Instance { get { return DefaultTimeProvider.instance; } } } I suspect that there's some subtle interplay going on with static initialization where the runtime is actually allowed to access TimeProvider.Current before all static initialization has finished, but I can't quite put my finger on it. Any help is appreciated.

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  • Is there a way to make sure classes implementing an Interface implement static methods?

    - by Tobias Kienzler
    Frist of all, I read erickson's usefull reply to "Why can’t I define a static method in a Java interface?". This question is not about the "why" but about the "how then?". So basically I want one Interface to provide both usual methods and e.g. a getSimilarObject method. For (a made up) example public interface ParametricFunction { /** @return f(x) using the parameters */ static abstract public double getValue(double x, double[] parameters); /** @return The function's name */ static abstract public String getName(); } and then public class Parabola implements ParametricFunction { /** @return f(x) = parameters[0] * x² + parameters[1] * x + parameters[2] */ static public double getValue(double x, double[] parameters) { return ( parameters[2] + x*(parameters[1] + x*parameters[0])); } static public String getName() { return "Parabola"; } } Since this is not allowed in the current Java standard, what is the closest thing to this? The idea behind this is putting several ParametricFunction's in a package and use Reflection to list them all, allowing the user to pick e.g. which one to plot. Obviously one could provide a loader class containing an array of the available ParametricFunction's, but every time a new one is implemented one has to remember adding it there, too.

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  • "The specified type was not recognized" exception when trying to invoke a webservice call

    - by fretje
    I'm trying to call a third party webservice using WSE 3.0 as a client in Visual Studio 2005. The call works fine and I can see that I get a good response (I have tracing enabled), but apparently the xml parser chokes over it. I always get an InvalidOperationException: There is en error in the XML document. with an InnerException: The specified type was not recognized: name='Map', namespace='http://xml.apache.org/xml-soap', at <bevoegdheid xmlns=''>. This is the relevant part of the response: <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ns1="http://xml.apache.org/xml-soap" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:ns2="https://acceptatie.cartalk.nl/Soap/Apk" SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"> <SOAP-ENV:Body> <SOAP-ENV:opvragenKeurmeesterGegevensResponse> <opvragenKeurmeesterGegevensReturn xsi:type="ns2:Backend_Apk_Result_OpvragenKeurmeesterGegevens"> <naam xsi:type="xsd:string">A name</naam> ... <bevoegdheid SOAP-ENC:arrayType="ns1:Map[2]" xsi:type="SOAP-ENC:Array"> <item xsi:type="ns1:Map"> <item> <key xsi:type="xsd:string">soortBevoegdheid</key> <value xsi:type="xsd:string">AL</value> </item> ... </item> <item> ... </item> </bevoegdheid> <meldingSoort xsi:nil="true" /> <meldingNummer xsi:nil="true" /> <melding xsi:nil="true" /> </opvragenKeurmeesterGegevensReturn> </SOAP-ENV:opvragenKeurmeesterGegevensResponse> </SOAP-ENV:Body> </SOAP-ENV:Envelope> And this is how that "bevoegdheid" is defined in the wsdl: <xsd:element name="bevoegdheid" type="soap-enc:Array" /> There is no mention of a "Map" type anywhere in the wsdl. I have been googling around for this, but the only kind of answer I've found is something along the lines of The service uses rpc/encoded format which is harder to get interoperability with. If you can change the server to document/literal it is better. But as this is a third party service (which is already used by other clients), this is no option for us. Any other suggestions? How can I get the xml parser to recognize that "Map" type?

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  • why string is a reference type?

    - by saurabh
    We know that string is a reference type , so we have string s="God is great!"; but on the same note if i declare class say Employee which is a reference type so why below piece of code does not work ? Employee e = "Saurabh"; 2- How do we actually determine if a type is a reference type or value type?

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  • Create list of variable type

    - by Jan
    I am trying to create a list of a certain type. I want to use the List notation but all I know is a "System.Type" The type a have is variable. How can I create a list of a variable type? I want something similar to this code. public IList createListOfMyType(Type myType) { return new List<myType>(); }

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  • Need to cast to an object without knowing what type the object is

    - by jle
    I am trying to dynamically load my authentication server type based on a setting. I am hung up on how to cast to a type when I don't know the type. Type t = Type.GetType(WebConfigurationManager.AppSettings.Get("AuthenticationSvcImpl")); IAuthenticationService authCli = Activator.CreateInstance(t); return authCli.AuthenticateUser(login); I know there is Convert.ChangeType(), but that just converts to an object...

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  • Filtering data in LINQ with the help of where clause

    - by vik20000in
     LINQ has bought with itself a super power of querying Objects, Database, XML, SharePoint and nearly any other data structure. The power of LINQ lies in the fact that it is managed code that lets you write SQL type code to fetch data.  Whenever working with data we always need a way to filter out the data based on different condition. In this post we will look at some of the different ways in which we can filter data in LINQ with the help of where clause. Simple Filter for an array. Let’s say we have an array of number and we want to filter out data based on some condition. Below is an example int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; var lowNums =                 from num in numbers                 where num < 5                 select num;   Filter based on one of the property in the class. With the help of LINQ we can also filer out data from a list based on value of some property. var soldOutProducts =                 from prod in products                 where prod.UnitsInStock == 0                 select prod; Filter based on Multiple of the property in the class. var expensiveInStockProducts =         from prod in products         where prod.UnitsInStock > 0 && prod.UnitPrice > 3.00M         select prod; Filter based on the index of the Item in the list.In the below example we can see that we are able to filter data based on the index of the item in the list. string[] digits = { "zero", "one", "two", "three", "four", "five", "six"}; var shortDigits = digits.Where((digit, index) => digit.Length < index); There are many other way in which we can filter out data in LINQ. In the above post I have tried and shown few ways using the LINQ. Vikram

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  • RPi and Java Embedded GPIO: Big Data and Java Technology

    - by hinkmond
    Java Embedded and Big Data go hand-in-hand, especially as demonstrated by prototyping on a Raspberry Pi to show how well the Java Embedded platform can perform on a small embedded device which then becomes the proof-of-concept for industrial controllers, medical equipment, networking gear or any type of sensor-connected device generating large amounts of data. The key is a fast and reliable way to access that data using Java technology. In the previous blog posts you've seen the integration of a static electricity sensor and the Raspberry Pi through the GPIO port, then accessing that data through Java Embedded code. It's important to point out how this works and why it works well with Java code. First, the version of Linux (Debian Wheezy/Raspian) that is found on the RPi has a very convenient way to access the GPIO ports through the use of Linux OS managed file handles. This is key in avoiding terrible and complex coding using register manipulation in C code, or having to program in a less elegant and clumsy procedural scripting language such as python. Instead, using Java Embedded, allows a fast way to access those GPIO ports through those same Linux file handles. Java already has a very easy to program way to access file handles with a high degree of performance that matches direct access of those file handles with the Linux OS. Using the Java API java.io.FileWriter lets us open the same file handles that the Linux OS has for accessing the GPIO ports. Then, by first resetting the ports using the unexport and export file handles, we can initialize them for easy use in a Java app. // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); ... // Reset the port unexportFile.write(gpioChannel); unexportFile.flush(); // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); Then, another set of file handles can be used by the Java app to control the direction of the GPIO port by writing either "in" or "out" to the direction file handle. // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write("in"); // Or, use "out" for output directionFile.flush(); And, finally, a RandomAccessFile handle can be used with a high degree of performance on par with native C code (only milliseconds to read in data and write out data) with low overhead (unlike python) to manipulate the data going in and out on the GPIO port, while the object-oriented nature of Java programming allows for an easy way to construct complex analytic software around that data access functionality to the external world. RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; ... // Reset file seek pointer to read latest value of GPIO port raf[channum].seek(0); raf[channum].read(inBytes); inLine = new String(inBytes); It's Big Data from sensors and industrial/medical/networking equipment meeting complex analytical software on a small constraint device (like a Linux/ARM RPi) where Java Embedded allows you to shine as an Embedded Device Software Designer. Hinkmond

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  • SSIS Debugging Tip: Using Data Viewers

    - by Jim Giercyk
    When you have an SSIS package error, it is often very helpful to see the data records that are causing the problem.  After all, if your input has 50,000 records and 1 of them has corrupt data, it can be a chore.  Your execution results will tell you which column contains the bad data, but not which record…..enter the Data Viewer. In this scenario I have created a truncation error.  The input length of [lastname] is 50, but the output table has a length of 15.  When it runs, at least one of the records causes the package to fail.     Now what?  We can tell from our execution results that there is a problem with [lastname], but we have no idea WHICH record?     Let’s identify the row that is actually causing the problem.  First, we grab the oft’ forgotten Row Count shape from our toolbar and connect it to the error output from our input query.  Remember that in order to intercept errors with the error output, you must redirect them.     The Row Count shape requires 1 integer variable.  For our purposes, we will not reference the variable, but it is still required in order for the package to run.  Typically we would use the variable to hold the number of rows in the table and refer back to it later in our process.  We are simply using the Row Count as a “Dead End” for errors.  I called my variable RowCounter.  To create a variable, with no shapes selected, right-click on the background and choose Variable.     Once we have setup the Row Count shape, we can right-click on the red line (error output) from the query, and select Data Viewers.  In the popup, we click the add button and we will see this:     There are other fancier options we can play with, but for now we just want to view the output in a grid.  WE select Grid, then click OK on all of the popup windows to shut them down.  We should now see a grid with a pair of glasses on the error output line.     So, we are ready to catch the error output in a grid and see that is causing the problem!  This time when we run the package, it does not fail because we directed the error to the Row Count.  We also get a popup window showing the error record in a grid.  If there were multiple errors we would see them all.     Indeed, the [lastname] column is longer than 15 characters.  Notice the last column in the grid, [Error Code – Description].  We knew this was a truncation error before we added the grid, but if you have worked with SSIS for any length of time, you know that some errors are much more obscure.  The description column can be very useful under those circumstances! Data viewers can be used any time we want to see the data that is actually in the pipeline;  they stop the package temporarily until we shut them.  Also remember that the Row Count shape can be used as a “Dead End”.  It is useful during development when we want to see the output from a dataflow, but don’t want to update a table or file with the dataData viewers are an invaluable tool for both development and debugging.  Just remember to REMOVE THEM before putting your package into production

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