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  • c++ "interface"-like classes similar to Java?

    - by William the Coderer
    In Java, you can define an interface as a class with no actual code implementation, but only to define the methods that a class must implement. Those types can be passed as parameters to methods and returned from methods. In C++, a pure virtual class can't be used as a parameter or return type, from what I can tell. Any way to mimic Java's interface classes? I have a string class in C++, and several subclasses for different encodings (like UTFxxx, ISOxxx, etc) that derive from the base string class. However, since there are so many different encodings, the base class has no meaningful implementation. But it would serve well as an interface if I could handle it as its own object and calls to that object would call on the correct subclass it was inherited to.

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  • Drupal: how to upgrade a running production website to a dev version?

    - by FractalizeR
    Can you help me to understand, how do I do Drupal website deployment and development? Suppose, I developed 1.0 version of Berty&Frank website. I copied everything to their production server and it is alive and kicking now. Site is already full of contents and is growing. I am asked to add additional features to the website. I am now experimenting with the way how I can implement them in a dev version. I am creating/deleting content types, fill created nodes with demo data just to see how they look like etc. Now I found the way and I want to upgrade production website to the same structure as my dev version now. How do I do that? Is the only way to manually make every change I made in dev version?

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  • How can I bind dynamic data to DataGridTemplateColun in code?

    - by TuomoT
    I'm using DataGrid from CodePlex. I have objects (ICustomTypeDescriptor) that have properties 'name' 'description' 'c' 'd' and so on (the names are dynamic, and so is the value) and they have information behind them. I have templates for different types. And if I have to list the properties of a single element I can just bind to the values in xaml and use datatemplateselector (in datagridtemplatecolumn) which will pick the correct template. However, when I'm listing several of the elements, how can I use the selectors and the templates? How do I get the correct property bound to the template (two-way)? When ignoring the need for different templates, using DataGridTextColumn with bindings is very simple (and works, see example below), is there any way to use similar approach with the DataGridTemplateColumn? foreach (String propertyName in listOfPropertyNames) { DataGridTextColumn textColumn = new DataGridTextColumn() { Header = propertyName, Binding = new Binding() { Path = new PropertyPath(propertyName) } }; DataGrid.Columns.Add(textColumn); }

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  • Store database, good pattern for simultaneous access

    - by dygi
    I am kinda new to database designing so i ask for some advices or some kind of a good pattern. The situation is that, there is one database, few tables and many users. How should i design the database, or / and which types of queries should i use, to make it work, if users can interact with the database simultaneously? I mean, they have access to and can change the same set of data. I was thinking about transactions, but I am not sure, if that is the right / good / the only solution. I will appreciate some google keywords too.

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  • c++ function overloading, making fwrite/fread act like PHP versions

    - by Newbie
    I'm used to the PHP fwrite/fread parameter orders, and i want to make them the same in C++ too. I want it to work with char and string types, and also any data type i put in it (only if length is defined). I am total noob on c++, this is what i made so far: size_t fwrite(FILE *fp, const std::string buf, const size_t len = SIZE_MAX){ if(len == SIZE_MAX){ return fwrite(buf.c_str(), 1, buf.length(), fp); }else{ return fwrite(buf.c_str(), 1, len, fp); } } size_t fwrite(FILE *fp, const void *buf, const size_t len = SIZE_MAX){ if(len == SIZE_MAX){ return fwrite((const char *)buf, 1, strlen((const char *)buf), fp); }else{ return fwrite(buf, 1, len, fp); } } Should this work just fine? And how should this be done if i wanted to do it the absolutely best possible way?

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  • Is there a way to reference a certain class/interface/... by enclosing it with its namespace rather than a using directive "using namespace_name" ?!

    - by Ahmed
    Is there a way to reference a certain class/interface/... by enclosing it with its namespace rather than a using directive "using namespace_name" ?! As, I'm working on a website, which uses SAP .NET connector. I already added a reference for connector ddl, and while referencing its namespace "using namespace_name", or set class namespace to another one rather than connector namespace, I got error regarding connector classes with that error message "The type or namespace couldn't be found, are you missing a using directive or an assembly reference?". But while changing namespace name to connector namespace, everything is going well?! // Set namespace to be IDestinationConfiguration interface namespace. namespace SAP.Middleware.Connector { public class ConnectorConfiguration : IDestinationConfiguration { } } So, connector types forced me to set namespace of class to their namespace! Is this possible? If so, how?

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  • Doing a SetLength on an array passed into a proc by reference

    - by csharpdefector
    Hi All, Sure, even I can do this... var testarray : array of string; setlength(testarray, 5); but if I want to get clever and have a procedure into which I pass the array by referance like this I cant do it! procedure DoStuffWithArray(var passedarray : array of string); begin setlength(passedarray, 5); end; compiler says 'incompatible types' on the single line of code in my proc. I can do other stuff on the array like set set element values if i do a setlength before i call the proc, but I cannot do the setlength in my proc, which is what I want to do. Any help much appreciated, thanks all.

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  • Are macro definitions compatible between MIPS and Intel C compiler?

    - by Derek
    I seem to be having a problem with a macro that I have defined in a C program. I compile this software and run it sucessfully with the MIPS compiler. It builds OK but throws the error "Segmentation fault" at runtime when using icc. I compiled both of these on 64 bit architectures (MIPS on SGI, with -64 flag and icc on an intel platform). Is there some magic switch I need to use to make this work correctly on both system? I turned on warnings for the intel compiler, and EVERY one of the places in my program where a macro is invoked throws a warning. Usually something along the lines of mismatched types on the macro's parameters (int to char *) or some such thing.

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  • Is it possible to have SNMP Agent without MIB’s support??

    - by Divya mohan Singh
    hii, i am working on SNMP from last few days,i have develope a small application(SNMP Agent) which * Run on 161 port. * Have a tree structured OID support. * Respond to all Get,GetNext,Set Pdu Request types. * Tested with some SNMP Managers(free available) by get and set the values of the OID's. BUT,now question is when i tried it with Cacti it will not respond anything,but detect windows snmp service..it just respond to the requests of the SNMP Managers. So,Is it mandatory to provide mib with SNMP Agent??.

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  • Generic TypeIdenitifier convertion.How?

    - by John
    How do I convert the TypeIdenitifier to a class type? I need to use implicit convertion. type TMyChildArray<T>=class(TMyArray<T>) private FData:Array of T; procedure AddEnd(); end; TTypeIdenitifierParentClass=class(TAnotherParentClass) protected TestField:Cardinal; end; procedure TMyChildArray<T>.AddEnd(); var elem:T; begin for elem in Fdata do TTypeIdenitifierParentClass(elem).TestField:=0; end; I get "Invalid typecast" on the implicit convertion "TTypeIdenitifierParentClass(elem).TestField:=0;". The principle I want to use is that the TypeIdenitifier will represent a class that descends from TTypeIdenitifierParentClass.There are many class types,but all of them descend that class. How do I do this?

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  • Can I attach a .NET TraceListener to an externally running process?

    - by BBlake
    I am developing an application scheduling program that will run other applications using System.Diagnostics.Process. The external applications are of various types (some .NET and some not). For those external apps that have trace logging enabled, is there a way that I can attach the tracelistener of the parent/calling application to listen to and record all the trace output from the child/called application to the parent application's trace output? This is not primarily for debugging purposes. This is more to track trace output from all the various scheduled applications by collecting it into one place as much as possible. The scheduler app is still in the early design stages, but will be .NET, and I'm trying to clear up potential design issues before I get into it too far.

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  • Rapid Prototyping for Embedded Systems

    - by dr_pepper
    For doing prototyping on small embedded projects that require physical motion, what hardware prototyping tools are available? For my projects, I tend to spend more time finding parts (i.e. wood, aluminum, etc.) and making the proper cuts, measurements, and connections than writing the software and configuring the electrical hardware. Are there any affordable products that will enable me to create physical hardware that is strong enough to support motion? If not, what techniques or tools are available to help develop the physical hardware more quickly? Currently, I typically build my projects from wood and plastic scraps that I have lying around. What types of materials enable you to prototype more quickly? CLARIFICATION: By motion, I mean something that has to bear stress like a robot arm powered by a servo motor and could handle moving or carrying 1-2 lbs.

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  • Drupal node reference

    - by Nikunj Kotecha
    I am using two content types - test_parent & test_child In test_child there are two fields, both of type datetime And in test_parent there are two fields, week_no & 7 node references I am using node_save to save a new node. After saving a node of parent type, and then saving the node of child type, i want to update the node it into the parent type. I have completed creation of both nodes from code, and also i am able to update nid in parent type from code. The problem is, the change in db is getting reflected in db but not on drupal node view. Even if i edit the node from drupal, it's showing -none- selected in node reference. Please help.

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  • What is an alternative to ADO.NET, but elegant way in C# to read Excel files

    - by Khnle
    ADO.NET just fails miserably when it's used to read Excel files where a column contains mixed data types. It appears that it tries to determine the data type of a column, and then assume the rest of the entire column is of the same data type. Here are some backgrounds: http://stackoverflow.com/questions/2968111/how-to-prevent-ado-net-from-altering-double-values-when-it-reads-from-excel-files http://blog.lab49.com/archives/196 What is an alternative approach that doesn't require automation, Excel to be co-installed, is simple (since the input excel file will only have one worksheet in each file).

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  • C++, create an instance from a static method

    - by Manux
    Hello, let's say I want my users to use only one class, say SpecialData. Now, this data class would have many methods, and depending on the type of data, the methods do different things, internally, but return externally similar results. Therefore my wanting to have one "public" class and other "private", child classes that would change the behavior of methods, etc... It would be amazingly more simple for some types of data that need to be built to do something like this: SpecialData& sm = SpecialData::new_supermatrix(); and new_supermatrix() would return a SuperMatrix instance, which inherits from most behaviors of SpecialData. my header: static SpecialData& new_supermatrix(); my cpp: SpecialData& SpecialData::new_supermatrix()(){ return SuperMatrix(MATRIX_DEFAULT_MAGNITUDE,1000,1239,FLOAT32,etc...); } The problem is, I get this error, which is probably logical due to the circumstances: invalid initialization of non-const reference of type ‘SpecialData&’ from a temporary of type ‘SpecialData’ So, any ideas?

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  • Web.xml ExceptionType

    - by andrew007
    Hi, is it possible to define two sections in the web.xml in order to catch two different exception types: <!-- general exception --> <error-page> <exception-type>**java.lang.Exception**</exception-type> <location>/generalError.jsp</location> </error-page> <!-- specific exception --> <error-page> <exception-type>org.myapp.myException</exception-type> <location>/sessionTimeout.jsp</location> </error-page> Does it has any conflict? THANKS!

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  • Can functions like sin() be redefined, in Fortran, C or Java?

    - by EOL
    Can a mathematical function like sin() be redefined, in Fortran, C or Java code, while preserving the default behavior of other mathematical functions like cos()? Or can another function named sin() but that accepts different argument types be defined in addition to the built-in sin()? I am interested in general features of these languages (I am thinking of applications like the implementation of non-usual number algebras). I tried to define a sin() function in a Fortran 95 program, but the intrinsic sin() function was called instead… Is there a way around this? what about C and Java?

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  • Direct flow depending on incoming dynamic type

    - by Improfane
    I have a listener class that accepts GUI change events in one method. The incoming event objects have a superclass of a type of GUI Event, the behaviour should depend on the dynamic type of the incoming variable. I wanted to do do lots of methods like: handleGUIEvent(EventChangedX event) handleGUIEvent(EventChangedY event) I am using a single event listener and receiving objects of various types but the behaviour should be different for each. What would you do? I do not want to use a switch statement as this would get unmaintainable.

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  • Drupal Views limiting content posted by group membership

    - by digital
    Hi, I have various different content types and I want to filter by using views. So say a block only displays content posted in groups that you are a member of. I've created my generic view which so far displays all content of that type, but I'm struggling with linking this to content only posted in groups your a member of. I've looked at the Organic Groups filters but no luck there. I suspect I might need to use some sort of relationship but I'm stuck there. Any help would be greatly appreciated.

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  • Where to put WPF specific code when using MVVM

    - by Surfbutler
    I'm just getting up to speed on MVVM, but all the examples I've seen so far are binding View controls to simple non-WPF specific data types such as strings and ints. However in our app I want to be able to set a button's border brush based on a number in the Model. At the moment, I translate the number into a brush in the ViewModel to keep the View XAML only, but is that right? I don't like putting WPF specific code in the ViewModel, but equally I don't like the idea of putting code-behind on my View panel. Which is the best way? Thanks

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  • Are C++ Reads and Writes of an int atomic

    - by theschmitzer
    I have two threads, one updating an int and one reading it. This value is a statistic where the order of the read and write is irrelevant. My question is, do I need to synchronize access to this multi-byte value anyway? Or, put another way, can part of the write be complete and get interrupted, and then the read happen. For example, think of value = ox0000FFFF increment value to 0x00010000 Is there a time where the value looks like 0x0001FFFF that I should be worried about? Certainly the larger the type, the more possible something like this is I've always synchronized these types of accesses, but was curious what the community thought.

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  • How does Play recognize a particular websocket message?

    - by noncom
    I am looking at the websocket-chat example. It unveils much, but I still cannot get something. I understand how messages are received, processed and sent on the web page side. However, Play captures websocket messages by means of the receive method of an Akka actor. In the websocket-chat, there are several cases in this method, but I don't get, how does it know which websocket message should be mapped to which case. In fact, I don't understand the path that a websocket message follows upon entering Play's domain, how is it processed and how can different message types/kinds be sent from the webpage. I have not find any info or sources related to this. Could please someone explain this or point to some kind of a good reference? UPDATE: The link to the original example.

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  • gwt - Using List<Serializable> in a RPC call?

    - by Garagos
    I have a RPC service with the following method: public List<Serializable> myMethod(TransactionCall call) {...} But I get a warning when this method is analyzed, and then the rpc call fails Analyzing 'my.project.package.myService' for serializable types Analyzing methods: public abstract java.util.List<java.io.Serializable> myMethod(my.project.package.TransactionCall call) Return type: java.util.List<java.io.Serializable> [...] java.io.Serializable Verifying instantiability (!) Checking all subtypes of Object wich qualify for serialization It seems I can't use Serializable for my List... I could use my own interface instead (something like AsyncDataInterface, wich implements the Serializable interface) but the fact is that my method will return a list custom objects AND basic objects (such as Strings, int....). So my questions are: Is it a standart behaviour? (I can't figure out why I can't use this interface in that case) Does anyone have a workaround for that kind of situation?

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  • How do I map repeating columns in NHibernate without creating duplicate properties

    - by Ian Oakes
    Given a database that has numerous repeating columns used for auditing and versioning, what is the best way to model it using NHibernate, without having to repeat each of the columns in each of the classes in the domain model? Every table in the database repeats these same nine columns, the names and types are identical and I don't want to replicate it in the domain model. I have read the docs and I saw the section on inheritance mapping but I couldn't see how to make it work in this scenario. This seems like a common scenario because nearly every database I've work on has had the four common audit columns (CreatedBy, CreateDate, UpdatedBy, UpdateDate) in nearly every table. This database is no different except that it introduces another five columns which are common to every table.

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  • List<T> add method in C#

    - by Nano HE
    Hello. As I know. List Add method works as below. List<string> cities = new List<string>(); cities.Add("New York"); cities.Add("Mumbai"); cities.Add("Berlin"); cities.Add("Istanbul"); If I designed the data structure as this List<object> lstObj = new List<object>(); if (true) // string members { cities.Add("New York"); cities.Add("Istanbul"); } else // List obj members here { List<object> AListObject= new List<object>(); cities.Add(AListObject); // how to handle this? } Does the List Add method works or not if I add different types members in the same function.

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