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• Hello world/Console Project in Visual Studio 2008 64 bit

  - by grobartn

  So I am trying to run console 64 bit Hello World program. I have Windows 7 Enterprise x64 bit version. I have installed Visual Studio 2008 and have added all of components needed for 64 bit. I want to create simple console application. It turns out to be a problem. I have simple standard hello world project. I have created it using New Project - Empty project. I added main.cpp that contains this: #include <iostream> using namespace std; int main() { cout << "howdy\n"; } I added new configuration to the project by clicking on Config Manager and added x64 config. Compiled and it compiles. Tried running it and cmd.exe shoots up with following error: "The application has failed to start because its side-by-side configuration is in correct. Please see the application event log or use the command-line sxstrace.e xe tool for more detail. Press any key to continue . . . " Which set-up step if any I am missing. What am I doing wrong and how should I go about setting simple console hello world in 64 bit world. Thanks for any help

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• C++ Pointer member function with templates assignment with a member function of another class

  - by Agusti

  Hi, I have this class: class IShaderParam{ public: std::string name_value; }; template<class TParam> class TShaderParam:public IShaderParam{ public: void (TShaderParam::*send_to_shader)( const TParam&,const std::string&); TShaderParam():send_to_shader(NULL){} TParam value; void up_to_shader(); }; typedef TShaderParam<float> FloatShaderParam; typedef TShaderParam<D3DXVECTOR3> Vec3ShaderParam; In another class, I have a vector of IShaderParams* and functions that i want to send to "send_to_shader". I'm trying assign the reference of these functions like this: Vec3ShaderParam *_param = new Vec3ShaderParam; _param-send_to_shader = &TShader::setVector3; This is the function: void TShader::setVector3(const D3DXVECTOR3 &vec, const std::string &name){ //... } And this is the class with IshaderParams*: class TShader{ std::vector params; public: Shader effect; std::string technique_name; TShader(std::string& afilename):effect(NULL){}; ~TShader(); void setVector3(const D3DXVECTOR3 &vec, const std::string &name); When I compile the project with Visual Studio C++ Express 2008 I recieve this error: Error 2 error C2440: '=' :can't make the conversion 'void (__thiscall TShader::* )(const D3DXVECTOR3 &,const std::string &)' a 'void (__thiscall TShaderParam::* )(const TParam &,const std::string &)' c:\users\isagoras\documents\mcv\afoc\shader.cpp 127 Can I do the assignment? No? I don't know how :-S Yes, I know that I can achieve the same objective with other techniques, but I want to know how can I do this..

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• How to extract ALL typedefs and structs and unions from c++ source

  - by Michael Wells

  I have inherited a Visual Studio project that contains hundreds of files. I would like to extract all the typedefs, structs and unions from each .h/.cpp file and put the results in a file). Each typdef/struct/union should be on one line in the results file. This would make sorting much easier. typdef int myType; struct myFirstStruct { char a; int b;...}; union Part_Number_Serial_Number_Part_2_Response_Message_Type {struct{Message_Response_Head_Type Head; Part_Num_Serial_Num_Part_2_Report_Array Part_2_Report; Message_Tail_Type Tail;} Data; BYTE byData[140];}myUnion; struct { bool c; int d;...}mySecondStruct; My problem is, I do not know what to look for (grammar of typedef/structs/unions) using a regular expression. I cannot believe that nobody has done this before (I googled and have not found anything on this). Does anyone know the regular expressions for these? (Note some are commented out using // others /* */) Or a tool to accomplish this. Edit: I am toying with the idea of autogenerating source code and/or dialogs for modifying messages that use the underlying typedef/struct/union. I was going to use the output to generate an XML file that could be used for this reason. The source for these are in C/C++ and used in almost all my projects. These projects are usually NOT in C/C++. By using the XML version I would only need to update/add the typedef/struct/union only in one place and all the projects would be able to autogen the source and/or dialogs.

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• Using an ActiveX control without a form/dialog/window in C++, VS 2008

  - by younevertell

  an ActiveX control generated by Visual Basic 6, very old stuff, it has a couple of methods and one event. now I have to use the control in C++, visual studio 2008, but I don't like to generate a form/dialog/window as constainer. I add some MFC class From ActiveX Control. Now the wrap class has all the methods defined in the ActiveX control. I definitely need add event handler to take care of the event fired by ActiveX control. With a form/dialgue/window, it could be done by below BEGIN_EVENTSINK_MAP ON_EVENT. My questions are 1. how to add the event handler without a form/dialgue/window. Is this impossible? 2. Could I manually add constructor in the ActiveX control wrap class, so I could use new operator to get an instance on the heap? Thanks Add the Event Sinks Map near the start of the definition (.cpp) file. The BEGIN_EVENTSINK_MAP macro takes the container's Class name, then the base class name as parameters. The container's class name is used again in the AFX_EVENTSINK_MAP macro and the ON_EVENT macro.

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• Using group_by with fields_for and accepts_nested_attributes_for

  - by Derek

  I have a the following rails models: class Release < ActiveRecord::Base has_many :release_questionnaires, :dependent => :destroy accepts_nested_attributes_for :release_questionnaires ... end class class ReleaseQuestionnaire < ActiveRecord::Base belongs_to :release belongs_to :milestone ... end class In my view code, I have the following form. <% form_for @release, ... do |f| %> ... <table class="questionnaires"> <% f.fields_for :release_questionnaires, @release.release_questionnaires.sort_by{|ra| ra.questionnaire.name} do |builder| %> ... <% end %> </table> <% end %> This works and allows me to view and edit the questionnaires as desired. However, I have an additional requirement to break the questionnaires out into their own tables grouped by the milestone they are associated to, rather than in a single table. It appears as though the group_by method is design to accomplish this, but I cannot get it to work as desired inside the tag. It may be that I'm missing something obvious, as I am a beginner... Any help is appreciated.

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• correct way of initializing variables

  - by OVERTONE

  ok this is just a shot in the dark but it may be the cause of most of the errors ive gotten. when your initializing something. lets say a smal swing program. would it go liek this variables here { private Jlist contactList; String [] contactArray; ArrayList <String> contactArrayList; ResultSet namesList constructor here public whatever() { GridLayout aGrid = new GridLayout(2,2,10,10); contact1 = new String(); contact2 = new String(); contact3 = new String(); contactArrayList = new ArrayList<String>(); // is something supposed too go in the () of this JList? contactList = new JList(); contactArray = new String[5]; from1 =new JLabel ("From: " + contactArray[1]); gridlayout.add(components)// theres too many components to write onto SO. } // methods here public void fillContactsGui() { createConnection(); ArrayList<String> contactsArrayList = new ArrayList<String>(); while (namesList.next()) { contactArrayList.add(namesList.getString(1)); ContactArray[1] = namesList[1]; } } i know this is probably a huge beginner question but this is the code ive gotten used too. im initializing thigns three and fours times without meaning too because im not sure where they gp. can anyone shed some light on this? p.s. sorry for the messy sample code. i done my best.

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• git commit best practices

  - by Ivan Z. Siu

  I am using git to manage a C++ project. When I am working on the projects, I find it hard to organize the changes into commits when changing things that are related to many places. For example, I may change a class interface in a .h file, which will affect the corresponding .cpp file, and also other files using it. I am not sure whether it is reasonable to put all the stuff into one big commit. Intuitively, I think the commits should be modular, each one of them corresponds to a functional update/change, so that the collaborators could pick things accordingly. But seems that sometimes it is inevitable to include lots of files and changes to make a functional change actually work. Searching did not yield me any good suggestion or tips. Hence I wonder if anyone could give me some best practices when doing commits. Thanks! PS. I've been using git for a while and I know how to interactively add/rebase/split/amend/... What I am asking is the PHILOSOPHY part.

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• Does it ever make sense to make a fundamental (non-pointer) parameter const?

  - by Scott Smith

  I recently had an exchange with another C++ developer about the following use of const: void Foo(const int bar); He felt that using const in this way was good practice. I argued that it does nothing for the caller of the function (since a copy of the argument was going to be passed, there is no additional guarantee of safety with regard to overwrite). In addition, doing this prevents the implementer of Foo from modifying their private copy of the argument. So, it both mandates and advertises an implementation detail. Not the end of the world, but certainly not something to be recommended as good practice. I'm curious as to what others think on this issue. Edit: OK, I didn't realize that const-ness of the arguments didn't factor into the signature of the function. So, it is possible to mark the arguments as const in the implementation (.cpp), and not in the header (.h) - and the compiler is fine with that. That being the case, I guess the policy should be the same for making local variables const. One could make the argument that having different looking signatures in the header and source file would confuse others (as it would have confused me). While I try to follow the Principle of Least Astonishment with whatever I write, I guess it's reasonable to expect developers to recognize this as legal and useful.

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• Callback function and function pointer trouble in C++ for a BST

  - by Brendon C.

  I have to create a binary search tree which is templated and can deal with any data types, including abstract data types like objects. Since it is unknown what types of data an object might have and which data is going to be compared, the client side must create a comparison function and also a print function (because also not sure which data has to be printed). I have edited some C code which I was directed to and tried to template, but I cannot figure out how to configure the client display function. I suspect variable 'tree_node' of class BinarySearchTree has to be passed in, but I am not sure how to do this. For this program I'm creating an integer binary search tree and reading data from a file. Any help on the code or the problem would be greatly appreciated :) Main.cpp #include "BinarySearchTreeTemplated.h" #include <iostream> #include <fstream> #include <string> using namespace std; /*Comparison function*/ int cmp_fn(void *data1, void *data2) { if (*((int*)data1) > *((int*)data2)) return 1; else if (*((int*)data1) < *((int*)data2)) return -1; else return 0; } static void displayNode() //<--------NEED HELP HERE { if (node) cout << " " << *((int)node->data) } int main() { ifstream infile("rinput.txt"); BinarySearchTree<int> tree; while (true) { int tmp1; infile >> tmp1; if (infile.eof()) break; tree.insertRoot(tmp1); } return 0; } BinarySearchTree.h (a bit too big to format here) http://pastebin.com/4kSVrPhm

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• Unresolved external symbol error in c++

  - by Crystal

  I am trying to do a simple hw problem involving namespace, static data members and functions. I am getting an unresolved external symbol error Error 1 error LNK2001: unresolved external symbol "private: static double JWong::SavingsAccount::annualInterestRate" (?annualInterestRate@SavingsAccount@JWong@@0NA) SavingsAccount.obj SavingsAccount And I don't see why I am getting this error. Maybe I don't know something about static variables compared to regular data members that is causing this error. Here is my code: SavingsAccount.h file #ifndef JWONG_SAVINGSACCOUNT_H #define JWONG_SAVINGSACCOUNT_H namespace JWong { class SavingsAccount { public: // default constructor SavingsAccount(); // constructor SavingsAccount(double savingsBalance); double getSavingsBalance(); void setSavingsBalance(double savingsBalance); double calculateMonthlyInterest(); // static functions static void modifyInterestRate(double newInterestRate); static double getAnnualInterestRest(); private: double savingsBalance; // static members static double annualInterestRate; }; } #endif SavingsAccount.cpp file #include <iostream> #include "SavingsAccount.h" // default constructor, set savingsBalance to 0 JWong::SavingsAccount::SavingsAccount() : savingsBalance(0) {} // constructor JWong::SavingsAccount::SavingsAccount(double savingsBalance) : savingsBalance(savingsBalance) {} double JWong::SavingsAccount::getSavingsBalance() { return savingsBalance; } void JWong::SavingsAccount::setSavingsBalance(double savingsBalance) { this->savingsBalance = savingsBalance; } // returns monthly interest and sets savingsBalance to new amount double JWong::SavingsAccount::calculateMonthlyInterest() { double monthlyInterest = savingsBalance * SavingsAccount::annualInterestRate / 12; setSavingsBalance(savingsBalance + monthlyInterest); return monthlyInterest; } void JWong::SavingsAccount::modifyInterestRate(double newInterestRate) { SavingsAccount::annualInterestRate = newInterestRate; } double JWong::SavingsAccount::getAnnualInterestRest() { return SavingsAccount::annualInterestRate; }

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• Modify existing struct alignment in Visual C++

  - by Crend King

  Is there a way to modify the member alignment of an existing struct in Visual C++? Here is the background: I use an 3rd-party library, which uses several structs. To fill up the structs, I pass the address of the struct instance to some functions. Unfortunately, the functions only returns unaligned buffer, so that data of some members are always wrong. /Zp is out of choice, since it breaks the other parts of the program. I know #pragma pack modifies the alignment of the following struct, but I do not want to copy the structs into my code, for the definitions in the library might change in the future. Sample code: test.h: struct am_aligned { BYTE data1[10]; ULONG data2; }; test.cpp: include "test.h" // typedef alignment(1) struct am_aligned am_unaligned int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) { char buffer[20] = {}; for (int i = 0; i < sizeof(unaligned_struct); i++) { buffer[i] = i; } am_aligned instance = *(am_aligned*) buffer; return 0; } instance.data2 is 0x0f0e0d0c, while 0x0d0c0b0a is desired. The commented line does not work of course. Thanks for help!

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• Putting all methods in class definition

  - by Amnon

  When I use the pimpl idiom, is it a good idea to put all the methods definitions inside the class definition? For example: // in A.h class A { class impl; boost::scoped_ptr<impl> pimpl; public: A(); int foo(); } // in A.cpp class A::impl { // method defined in class int foo() { return 42; } // as opposed to only declaring the method, and defining elsewhere: float bar(); }; A::A() : pimpl(new impl) { } int A::foo() { return pimpl->foo(); } As far as I know, the only problems with putting a method definition inside a class definition is that (1) the implementation is visible in files that include the class definition, and (2) the compiler may make the method inline. These are not problems in this case since the class is defined in a private file, and inlining has no effect since the methods are called in only one place. The advantage of putting the definition inside the class is that you don't have to repeat the method signature. So, is this OK? Are there any other issues to be aware of?

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• How does one make the camera on the iphone appear from the app delegate? Is it possible?

  - by K-RAN

  I'm just playing around with a simple program that opens the camera. That's literally all that I want to do. I'm a beginner and I believe that I have the basics down in terms of UI management for the iPhone so I decided to give this one a whirl. What I'm trying to do right now is... - (BOOL) application:(UIApplication*) application didFinishLaunchingWithOptions:(NSDictionary*) launchOptions { UIImagePickerController * camera = [[UIImagePickerController alloc] init]; camera.delegate = self; camera.sourceType = UIImagePickerControllerSourceTypeCamera; camera.allowsEditing = NO; camera.showsCameraControls = NO; [viewController presentModalViewController:camera animated:NO]; [window addSubview:viewController.view]; [window makeKeyAndVisible]; return YES: } So basically, initialize the camera, set some things and show it in the main view. I set the camera's delegate to self because this code is placed in the delegate class (and yes, the delegate class is conforming to UIImagePickerControllerDelegate && UINavigationControllerDelegate). Main problem right now is that nothing is appearing on the screen. I have absolutely no idea what I'm doing wrong, especially since the program is building correctly with no errors or warnings... Any help is appreciated! Thanks a lot :D

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• Retrieve the Value of An Integer Variable

  - by Abluescarab

  This is probably easily figured out (I feel very stupid right now), but I can't find a solution anywhere, for some reason. Perhaps I'm not searching for the right thing. And maybe it's in some beginner tutorial I haven't watched. Anyway, I was wondering how to retrieve the value of an integer variable in C++? I know you can use cin.getline() for string variables, but I received an error message when I attempted that with an integer variable (and rightfully so, I know it was wrong, but I was looking for a solution). My project is a Win32 console application. What I'm trying to do is ask a user to input a number, stored in the variable n. Then I take the value of n and perform various math functions with it. In my header file, I have string, windows, iostream, stdio, math, and fstream. Do I need to add another library? There's not much more to tell. I can post my code if I must. EDIT: cout << "TEST SINE"; cout << "\nPlease enter a number.\n\n"; cin >> n; break; Here's the code I'm trying to use. Is this all I need to do? If so, how do I incorporate the variable so I can test it using sin, cos, and tan? Yet again, thanks ahead of time.

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• Define an empty array in Perl class new()

  - by Laimoncijus

  Hi, I am just beginner with Perl, so if it sounds stupid - sorry for that :) My problem is - I am trying to write a class, which has an empty array, defined in constructor of a class. So I am doing this like this: package MyClass; use strict; sub new { my ($C) = @_; my $self = { items => () }; bless $self, ref $C || $C; } sub get { return $_[0]->{items}; } 1; Later I am testing my class with simple script: use strict; use Data::Dumper; use MyClass; my $o = MyClass->new(); my @items = $o->get(); print "length = ", scalar(@items), "\n", Dumper(@items); And while running the script I get following: $ perl my_test.pl length = 1 $VAR1 = undef; Why am I doing wrong what causes that I get my items array filled with undef? Maybe someone could show me example how the class would need to be defined so I would not get any default values in my array? Thanks!

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• Remote connection to SQL Server Express fails

  - by worlds-apart89

  I have two computers that share the same Internet IP address. Using one of the computers, I can remotely connect to a SQL Server database on the other. Here is my connection string: SqlConnection connection = new SqlConnection(@"Data Source=192.168.1.101\SQLEXPRESSNI,1433;Network Library=DBMSSOCN;Initial Catalog=FirstDB;Persist Security Info=True;User ID=username;Password=password;"); 192.168.1.101 is the server, SQLEXPRESSNI is the SQL Server instance name, and FirstDB is the name of the database. Now, I have another computer with a different Internet IP address. I want to connect to the server above using the third computer that does not belong to my local area network. I dont have access to that third computer at the moment, so I want to use (if possible) the client computer in LAN again. SqlConnection connection = new SqlConnection(@"Data Source=SharedInternetIP\SQLEXPRESSNI,1433;Network Library=DBMSSOCN;Initial Catalog=FirstDB;Persist Security Info=True;User ID=username;Password=password;"); Does not work Note that I am a beginner, so I am not quite sure what I am doing even though I know what I want to do. By passing the Internet IP to the SqlConnection object rather than the local IP address, how can I successfully connect to the server computer, using the client computer in the same network? Also note that my ultimate goal is to connect to the server with an external client, but I don't have access to that computer right now. I'd appreciate any help.

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• Java and Jasper

  - by bhargava

  Hey Guys, I have integrated Jasper Reports on my netbeans platform and i am able to generate reports using the following code. Map<String, Object> params = new HashMap<String, Object>(); Connection conn = DriverManager.getConnection("databaseUrl", "userid","password"); JasperReport jasperReport = JasperCompileManager.compileReport(reportSource); JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, params, conn); JasperExportManager.exportReportToHtmlFile(jasperPrint, reportDest); JasperViewer.viewReport(jasperPrint); This stuff works perfect. But not i am trying to integrate Jasper with GWT.I have my server as glass fish server. I am getting the Connection object using the followind code. public static Connection getConnection() { try { String JNDI = "JNDI name"; InitialContext initCtx = new InitialContext(); javax.sql.DataSource ds = (javax.sql.DataSource) initCtx.lookup(JNDI); Connection conn = (Connection) ds.getConnection(); return conn; } catch (Exception ex) { ex.printStackTrace(); } return null; } and then Map params = new HashMap(); JasperReport jasperReport = JasperCompileManager.compileReport(reportSource); JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, params, getConnection()); JasperExportManager.exportReportToHtmlFile(jasperPrint, reportDest); JasperViewer.viewReport(jasperPrint); but i always get Error.I am implementing this on Server.I am having RPC calls to get this method to work when a button is clicked. Can you please help me how to work on this.(That is to integrate Jasper reports with GWT). I would highly appreciate any explanation with some code as i am just a beginner. Thanks

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• c++ struct size

  - by kiokko89

  struct CExample { int a; } int main(int argc, char* argv[]) { CExample ce; CExample ce2; cout << "Size:" << sizeof(ce)<< " Address: "<< &ce<< endl; cout << "Size:" << sizeof(ce2)<< " Address: "<< &ce2 << endl; CExample ceArr[2]; cout << "Size:" << sizeof(ceArr[0])<< " Address: "<<&ceArr[0]<<endl; cout << "Size:" << sizeof(ceArr[1])<< " Address: "<<&ceArr[1]<<endl; return 0; } Excuse me I'm just a beginner but i'd like to know why with this code, there is a difference of 12 bytes between the addresses of the first two objects(ce and ce2) (i thought about data allignment), but there is only a difference of 4 bytes between the two objects in the array. Sorry for my bad English...

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• libarchive reads too many chars when extracting a file

  - by ojreadmore

  I've written a C program to extract files from a tar archive using libarchive. I'd like to extract a file from this archive and print it to standard output. But I get extra characters. It's garbage, but it's from another file (possibly adjacent to it in the archive.) I expect output to end at </html>. Here is the code that reads this tar file. libarchive 2.8.3 compiled on mac os X 10.6.3. gcc 4.2 x86_64 ls -l vendar-definition.html gives me 1921 for the file size. And so shows tar tfv 0000.tar | grep vendar-definition.html. So reports the C output that states the file size. To me this seems correct. Two possibilities I can see for why my output is not as expected: 1. I've made a beginner's mistake or 2. multibyte characters in the archive files has something to do with it.

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• Three most critical programming concepts

  - by Todd

  I know this has probably been asked in one form or fashion but I wanted to pose it once again within the context of my situation (and probably others here @ SO). I made a career change to Software Engineering some time ago without having an undergrad or grad degree in CS. I've supplemented my undergrad and grad studies in business with programming courses (VB, Java,C, C#) but never performed academic coursework in the other related disciplines (algorithms, design patterns, discrete math, etc.)...just mostly self-study. I know there are several of you who have either performed interviews and/or made hiring decisions. Given recent trends in demand, what would you say are the three most essential Comp Sci concepts that a developer should have a solid grasp of outside of language syntax? For example, I've seen blog posts of the "Absolute minimum X that every programmer must know" variety...that's what I'm looking for. Again if it's truly a redundancy please feel free to close; my feelings won't be hurt. (Closest ones I could find were http://stackoverflow.com/questions/164048/basic-programming-algorithmic-concepts- which was geared towards a true beginner, and http://stackoverflow.com/questions/648595/essential-areas-of-knowledge-which I didn't feel was concrete enough). Thanks in advance all! T.

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• GNU/Linux developement n00b needs help porting C++ application from windows to GNU/Linux.

  - by AndrejaKo

  Hi! These questions may not be perfectly suited for this site, so I apologize in advance for asking them here. I'm trying to port a computer game from windows to GNU/Linux. It uses Ogre3D,CEGUI, ogreogg and ogrenewt. As far as I know all dependencies work on GNU/Linux and in the game itself there is no ooze-specific code. Here's the questions part: Is there any easy way to port visual studio 2008 project to GNU/Linux tool-chain? How do I manage dependencies? In Visual Studio, I'd just add them in property sheets or default directories. I assume on GNU/Linux autoconf and make take care of that, but in which way? Do I have to add each .cpp and .hpp manually or is there some way to automate things? How do I solve the problem of dependencies on different locations on different systems? I'd like to use Eclipse as IDE under GNU/Linux. I know that the best answer to most of my questions is RTFM, but I'm not sure what I exactly need and where to start looking.

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• (RoR) How to: link multiple apps, multiple URLs, one database

  - by Samson

  Hello. I am currently developing a site using Ruby on Rails. I am still a beginner who just started around a month ago. I use InstantRails on Windows 7. Here's my question. Let's say app A is functional using MYSQL database A_development. The files such as views and controller are under folder 'A'. I now know how to, say for example, link www.app.com to this app by opening port 80 and changing some lines in the mySQL config. In this app, you can register your username, login, and post some messages. I now want to create some pretty identical apps say B and C. The only thing different will be the posts that shows, and the views. You can still log in with the same username, and everything is saved in the same database. I now want the URLs to look something like A.app.com leading to app A, B.app.com leading to app B, etc. Can that be achieved? How? I've been googling for a few days already and I'm still lost. As I'm new to this forum, I'm not quite sure what info do you guys need. Please list and I'll provide them asap. Any help will be appreciated! Thanks.

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• Are there good reasons not to use an ORM?

  - by hangy

  During my apprenticeship, I have used NHibernate for some smaller projects which I mostly coded and designed on my own. Now, before starting some bigger project, the discussion arose how to design data access and whether or not to use an ORM layer. As I am still in my apprenticeship and still consider myself a beginner in enterprise programming, I did not really try to push in my opinion, which is that using an object relational mapper to the database can ease development quite a lot. The other coders in the development team are much more experienced than me, so I think I will just do what they say. :-) However, I do not completely understand two of the main reasons for not using NHibernate or a similar project: One can just build one’s own data access objects with SQL queries and copy those queries out of Microsoft SQL Server Management Studio. Debugging an ORM can be hard. So, of course I could just build my data access layer with a lot of SELECTs etc, but here I miss the advantage of automatic joins, lazy-loading proxy classes and a lower maintenance effort if a table gets a new column or a column gets renamed. (Updating numerous SELECT, INSERT and UPDATE queries vs. updating the mapping config and possibly refactoring the business classes and DTOs.) Also, using NHibernate you can run into unforeseen problems if you do not know the framework very well. That could be, for example, trusting the Table.hbm.xml where you set a string’s length to be automatically validated. However, I can also imagine similar bugs in a “simple” SqlConnection query based data access layer. Finally, are those arguments mentioned above really a good reason not to utilise an ORM for a non-trivial database based enterprise application? Are there probably other arguments they/I might have missed? (I should probably add that I think this is like the first “big” .NET/C# based application which will require teamwork. Good practices, which are seen as pretty normal on Stack Overflow, such as unit testing or continuous integration, are non-existing here up to now.)

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• Creating a new object destroys an older object with different name in C++

  - by Mikael

  First question here! So, I am having some problems with pointers in Visual C++ 2008. I'm writing a program which will control six cameras and do some processing on them so to clean things up I have created a Camera Manager class. This class handles all operations which will be carried out on all the cameras. Below this is a Camera class which interacts with each individual camera driver and does some basic image processing. Now, the idea is that when the manager is initialised it creates two cameras and adds them to a vector so that I can access them later. The catch here is that when I create the second camera (camera2) the first camera's destructor is called for some reason, which then disconnects the camera. Normally I'd assume that the problem is somewhere in the Camera class, but in this case everything works perfectly as long as I don't create the camera2 object. What's gone wrong? CameraManager.h: #include "stdafx.h" #include <vector> #include "Camera.h" class CameraManager{ std::vector<Camera> cameras; public: CameraManager(); ~CameraManager(); void CaptureAll(); void ShowAll(); }; CameraManager.cpp: #include "stdafx.h" #include "CameraManager.h" CameraManager::CameraManager() { printf("Camera Manager: Initializing\n"); [...] Camera *camera1 = new Camera(NodeInfo,1, -44,0,0); cameras.push_back(*camera1); // Adding the following two lines causes camera1's destructor to be called. Why? Camera *camera2 = new Camera(NodeInfo,0, 44,0,0); cameras.push_back(*camera2); printf("Camera Manager: Ready\n"); }

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• How do I bind to a custom view in Cocoa using Xcode 4?

  - by Newt

  I'm a beginner when it comes to writing Mac apps and working with Cocoa, so please forgive my ignorance. I'm looking to create a custom view, that exposes some properties, which I can then bind to an NSObjectController. Since it's a custom view, the Bindings Inspector obviously doesn't list any of the properties I've added to the view that I can then bind to using Interface Builder. After turning to the Stackoverflow/Google for help, I've stumbled across a couple of possible solutions, but neither seem to be quite right for my situation. The first suggested creating an IBPlugin, which would then mean my bindings would be available in the Bindings Inspector. I could then bind the view to the controller using IB. Apparently IBPlugins aren't supported in Xcode 4, so that one's out the window. I'm also assuming (maybe wrongly) that IBPlugins are no longer supported because there's a better way of doing such things these days? The second option was to bind the controller to the view programmatically. I'm a bit confused as to exactly how I would achieve this. Would it require subclassing NSObjectController so I can add the calls to bind to the view? Would I need to add anything to the view to support this? Some examples I've seen say you'd need to override the bind method, and others say you don't. Also, I've noticed that some example custom views call [self exposeBinding:@"bindingName"] in the initializer. From what I gather from various sources, this is something that's related to IBPlugins and isn't something I need to do if I'm not using them. Is that correct? I've found a post on Stackoverflow here which seems to discuss something very similar to my problem, but there wasn't any clear winner as to the best answer. The last comment by noa on 12th Sept seems interesting, although they mention you should be calling exposeBinding:. Is this comment along the right track? Is the call to exposeBinding really necessary? Apologies for any dumb questions. Any help greatly appreciated.

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