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• What is the "Entity" reffering to in fluent Nhibernate Mapping Configuration?

  - by percent20

  I am trying to learn fluent nhibernate better so am doing a basic sample application from scratch, instead of using someone elses framework. However, I am finding I really don't understand what is going on in assigning mapping files. I have seen a lot of code examples which are all showing the same code, but nothing that spells it out. No description of how it works just that it works. Here is a code example that I see often. return Fluently.Configure() .Database(config) .Mappings(m => m.FluentMappings.AddFromAssemblyOf<Entity>()) .BuildSessionFactory(); So in the code example what is Entity? and how does that piece of code work? Part of me thinks it is the name of the assembly, but seeing as how the namespace I am using is usually the name of the assembly the compiler complains that I am using a namespace as a type. I feel this is important and am rather flustered by the fact I can't figure it out. Thanks

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• Using typedefs (or #defines) on built in types - any sensible reason?

  - by jb

  Well I'm doing some Java - C integration, and throught C library werid type mappings are used (theres more of them;)): #define CHAR char /* 8 bit signed int */ #define SHORT short /* 16 bit signed int */ #define INT int /* "natural" length signed int */ #define LONG long /* 32 bit signed int */ typedef unsigned char BYTE; /* 8 bit unsigned int */ typedef unsigned char UCHAR; /* 8 bit unsigned int */ typedef unsigned short USHORT; /* 16 bit unsigned int */ typedef unsigned int UINT; /* "natural" length unsigned int*/ Is there any legitimate reason not to use them? It's not like char is going to be redefined anytime soon. I can think of: Writing platform/compiler portable code (size of type is underspecified in C/C++) Saving space and time on embedded systems - if you loop over array shorter than 255 on 8bit microprocessor writing: for(uint8_t ii = 0; ii < len; ii++) will give meaureable speedup.

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• .NET 4.0 Generic Invariant, Covariant, Contravariant

  - by Sameer Shariff

  Here's the scenario i am faced with: public abstract class Record { } public abstract class TableRecord : Record { } public abstract class LookupTableRecord : TableRecord { } public sealed class UserRecord : LookupTableRecord { } public interface IDataAccessLayer<TRecord> where TRecord : Record { } public interface ITableDataAccessLayer<TTableRecord> : IDataAccessLayer<TTableRecord> where TTableRecord : TableRecord { } public interface ILookupTableDataAccessLayer<TLookupTableRecord> : ITableDataAccessLayer<TLookupTableRecord> where TLookupTableRecord : LookupTableRecord { } public abstract class DataAccessLayer<TRecord> : IDataAccessLayer<TRecord> where TRecord : Record, new() { } public abstract class TableDataAccessLayer<TTableRecord> : DataAccessLayer<TTableRecord>, ITableDataAccessLayer<TTableRecord> where TTableRecord : TableRecord, new() { } public abstract class LookupTableDataAccessLayer<TLookupTableRecord> : TableDataAccessLayer<TLookupTableRecord>, ILookupTableDataAccessLayer<TLookupTableRecord> where TLookupTableRecord : LookupTableRecord, new() { } public sealed class UserDataAccessLayer : LookupTableDataAccessLayer<UserRecord> { } Now when i try to cast UserDataAccessLayer to it's generic base type ITableDataAccessLayer<TableRecord>, the compiler complains that it cannot implicitly convert the type.

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• winsock compile crash

  - by ioil

  The following errors are from a file with just windows and winsock2 included. C:\Users\ioil\Desktop\dm\bin>dmc sockit.c typedef struct fd_set { ^ C:\Users\ioil\Desktop\dm\bin\..\include\win32\WINSOCK2.H(85) : Error: 'fd_set' is already defined } fd_set; ^ C:\Users\ioil\Desktop\dm\bin\..\include\win32\WINSOCK2.H(88) : Error: identifier or '( declarator )' expected struct timeval { ^ C:\Users\ioil\Desktop\dm\bin\..\include\win32\WINSOCK2.H(129) : Error: 'timeval' is already defined }; ^ C:\Users\ioil\Desktop\dm\bin\..\include\win32\WINSOCK2.H(132) : Error: identifier or '( declarator )' expected struct hostent { ^ C:\Users\ioil\Desktop\dm\bin\..\include\win32\WINSOCK2.H(185) : Error: 'hostent' is already defined Fatal error: too many errors --- errorlevel 1 C:\Users\ioil\Desktop\dm\bin> What's already been tried : placing the winsock.dll file in the same directory as the compiler and program to be compiled, placing it in the system32 directory, and entering it in the registry with the regsrv32 command. Don't really know where to go from here, appreciate any advice . . .

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• hiding inner class implementation using namespace

  - by Abruzzo Forte e Gentile

  Hi all I am developing a library and a would like to provide my users a public interface separate from the real implementatino that is hidden in a namespace. This way, I could change only the class HiddenQueue without changing myQueue that will be exposed to users only. If I put the C++ code of HiddenQueue in the myQueue.cpp file the compiler complains saying _innerQueue has incomplete type. I thought that the linker was able to resolve this. What I am doing wrong here? Thanks Afg // myQueue.h namespace inner{ class HiddenQueue; }; class myQueue{ public: myQueue(); ); private: inner::HiddenQueue _innerQueue; }; /////////////////////////// // myQueue.cpp namespace inner{ class HiddenQueue{}; };

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• C++: Cannot convert from foo& to foo*

  - by Rosarch

  I have a method: odp(foo& bar); I'm trying to call it: foo baz; odp(&baz); I get a compiler error: error C2664: "odp" cannot convert parameter 1 from 'foo *' to 'foo &' What am I doing wrong? Aren't I passing in a reference to baz? UPDATE: Perhaps I have a misconception about the relationship between pointers and references. I thought that they were the same, except references couldn't be null. Is that incorrect?

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• Converting ObjC Blocks to C# Lambas

  - by Sam

  I need some help converting an Objective-C block to C#. Here is the source ObjC: NSDate* addYear = [_calendar dateByAddingComponents:((^{ NSDateComponents* components = [NSDateComponents new]; components.month = 12; return components; })()) toDate:now options:0]; Now I tried the following in C#: NSDate date = _calendar.DateByAddingComponents((() => { NSDateComponents components = new NSDateComponents(); components.Month = 12; return components; })(), now, NSCalendarOptions.None); To which I get the following compiler error: Expression denotes a 'anonymous method' where a 'method group' was expected. Removing the parentheses around the lambda yields Cannot convert 'lambda expression' to non-delegate type 'MonoTouch.Foundation.NSDateComponents'. What is the correct C# syntax? I need to retain the closures as there are a lot more in the code base that I am porting.

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• How to pass a class method as an argument for another function in C++ and openGL?

  - by tsubasa

  I know this thing works: void myDisplay() { ... } int main() { ... glutDisplayFunc(myDisplay) ... } so I tried to include myDisplay() function to a class that I made. Because I want to overload it in the future with a different class. However, the compiler complains that argument of type 'void (ClassBlah::)()' does not match 'void(*)()' . Here is the what I try to make: class ClassBlah { .... void myDisplay() .... } ...... int main() { ... ClassBlah blah glutDisplayFunc(blah.myDisplay) ... } Does anybody knows how to fix this problem? Many thanks.

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• Generics Type issue

  - by JohnJohnGa

  ArrayList<Integer> arrI = new ArrayList<Integer>(); ArrayList arrO = arrI; // Warning /* It is ok to add a String as it is an ArrayList of Objects but the JVM will know the real type, arrO is an arrayList of Integer... */ arrO.add("Hello"); /* How I can get a String in an ArrayList<Integer> ?? Even if the compiler told me that I will get an Integer! */ System.out.println(arrI.get(0)); Anybody can explain what's happening here?

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• How does windows differentiate between regular exe and a .Net exe?

  - by Yogendra

  Hi All, This might be a duplicate entry. Excuse me if it is. I was asked in an interview as to how does Windows OS differentiate between regular exe and .Net exe. My reply was, when .Net exe is build, the compiler emits some information into the header. The information is PE32 or PE32+. windows verifies the header to determine if it needs to load the MSCOREE.dll which loads the CLR and executes the exe. I am not sure if my answer is correct ? Your inputs is appreciated.

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• How to make Visual C++ 9 not emit code that is actually never called?

  - by sharptooth

  My native C++ COM component uses ATL. In DllRegisterServer() I call CComModule::RegisterServer(): STDAPI DllRegisterServer() { return _Module.RegisterServer(FALSE); // <<< notice FALSE here } FALSE is passed to indicate to not register the type library. ATL is available as sources, so I in fact compile the implementation of CComModule::RegisterServer(). Somewhere down the call stack there's an if statement: if( doRegisterTypeLibrary ) { //<< FALSE goes here // do some stuff, then call RegisterTypeLib() } The compiler sees all of the above code and so it can see that in fact the if condition is always false, yet when I inspect the linker progress messages I see that the reference to RegisterTypeLib() is still there, so the if statement is not eliminated. Can I make Visual C++ 9 perform better static analysis and actually see that some code is never called and not emit that code?

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• Core Data produces Analyzer warnings

  - by RickiG

  Hi I am doing the final touch ups on an app and I am getting rid of every compiler/analyzer warning. I have a bunch of Class methods that wrap my apps access to Core Data entities. This is "provoking" the analyzer. + (CDProductEntity*) newProductEntity { return (CDProductEntity*)[NSEntityDescription insertNewObjectForEntityForName:@"CDProductEntity" inManagedObjectContext:[self context]]; } Which results in an Analyzer warning: Object with +0 retain counts returned to caller where a +1 (owning) retain count is expected In the method that calls the above Class Method I have this: CDProductEntity *newEntity = [self newProductEntity]; Which results in an Analyzer warning: Method returns an Objective-C object with a +1 retain count (owning reference) Explicitly releasing or autoreleasing a Core Data entity is usually very very bad, but is that what it is asking me to do here? First it tells me it has a +0 retain count and that is bad, then it tells me it has a +1 which is also bad. What can I do to ensure that I am either dealing with a Analyzer hiccup or that I release correctly? Thanks in advance

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• Suggestions for a django db structure

  - by rh0dium

  Hi Say I have the unknown number of questions. For example: Is the sky blue [y/n] What date were your born on [date] What is pi [3.14] What is a large integ [100] Now each of these questions poses a different but very type specific answer (boolean, date, float, int). Natively django can happily deal with these in a model. class SkyModel(models.Model): question = models.CharField("Is the sky blue") answer = models.BooleanField(default=False) class BirthModel(models.Model): question = models.CharField("What date were your born on") answer = models.DateTimeField(default=today) class PiModel(models.Model) question = models.CharField("What is pi") answer = models.FloatField() But this has the obvious problem in that each question has a specific model - so if we need to add a question later I have to change the database. Yuck. So now I want to get fancy - How do a set up a model where by the answer type conversion happens automagically? ANSWER_TYPES = ( ('boolean', 'boolean'), ('date', 'date'), ('float', 'float'), ('int', 'int'), ('char', 'char'), ) class Questions(models.model): question = models.CharField(() answer = models.CharField() answer_type = models.CharField(choices = ANSWER_TYPES) default = models.CharField() So in theory this would do the following: When I build up my views I look at the type of answer and ensure that I only put in that value. But when I want to pull that answer back out it will return the data in the format specified by the answer_type. Example 3.14 comes back out as a float not as a str. How can I perform this sort of automagic transformation? Or can someone suggest a better way to do this? Thanks much!!

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• How to auto-deploy web-app

  - by Frankie

  Hello, I'm trying to make sense on the best way to do automatize a series of things in a row in order to deploy a web-app and haven't yet came up with a suitable solution. I would like to: use google's compiler.jar to minify my JS use yahoo's yui-compressor.jar to minify my CSS access a file and change a string so that header files like "global.css?v=21" get served the correct version deploy the app (sftp, mercurial or rsync?) omitting certain directories like "/userfiles" Can you guys put me on the right track to solve this? Thank you!

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• C# extern int ? How do I make a global var across classes and namespaces ?

  - by dr d b karron

  Dear C#'ers; As an old C/C++ programmer, I want to keep a global int counter across all of MY namespaces and classes. Public static extern int EventCount; Is not working; the VS2010 compiler won't let me have an extern int. Even with a DLLImport. [DllImport ( "SilverlightApplication37.dll" )] public static extern int EventCount; VS2010 complains Error 1 The modifier 'extern' is not valid for this item so how do i have a global int across all my code ? Cheers! dr.K

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• How does c# type safety affect the garbage collection?

  - by Indeera

  I'm dealing with code that handles large buffers ( 100MB) and manipulation of these is done in unsafe blocks. I'd like to refactor these to avoid unsafe code. I'm wondering about the likely memory performance gains (positive/negative/neutral) before I embark on that. I assert that if the compiler can verify types, it could possibly generate better code and that could also mean good GC performance. Is this a valid assertion? What is your experience? Thanks.

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• Using memory mapping in C for reading binary

  - by user1320912

  I am trying to read data from a binary file and process it.It is a very large file so I thought I would use memory mapping. I am trying to use memory mapping so I can read the file byte by byte. I am getting a few compiler errors while doing this. I am doing this on a linux platform #include <unistd.h> #include <sys/types.h> #include <sys/mman.h> int fd; char *data; fd = open("data.bin", O_RDONLY); pagesize = 4000; data = mmap((caddr_t)0, pagesize, PROT_READ, MAP_SHARED, fd, pagesize); The errors i get are : caddr not initialized, R_RDONLY not initialized, mmap has too few arguments. Could someone help me out ?

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• Fix DB duplicate entries (MySQL bug)

  - by Silence

  I'm using MySQL 4.1. Some tables have duplicates entries that go against the constraints. When I try to group rows, MySQL doesn't recognise the rows as being similar. Example: Table A has a column "Name" with the Unique proprety. The table contains one row with the name 'Hach?' and one row with the same name but a square at the end instead of the '?' (which I can't reproduce in this textfield) A "Group by" on these 2 rows return 2 separate rows This cause several problems including the fact that I can't export and reimport the database. On reimporting an error mentions that a Insert has failed because it violates a constraint. In theory I could try to import, wait for the first error, fix the import script and the original DB, and repeat. In pratice, that would take forever. Is there a way to list all the anomalies or force the database to recheck constraints (and list all the values/rows that go against them) ? I can supply the .MYD file if it can be helpful.

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• How to define and use a local variable in aspx page?

  - by Bruskvilla

  Hello how can I define a local variable in aspx page. I just did the below code it gives errors. I'm new please help. Thanks. <% Devamsizlik.Models.DevamDurumu obj; % <% foreach (var item in Model){ %> .....blabla <% obj = item; %> <%} %>//end of foreach < p <%: Html.ActionLink("Create New", "DevamsizEkle", new { ogrId = obj.devamOgrenciID }, new { subeId = obj.devamsizlikSubeID })% < / p > ....< /p cause a compilation error Compiler Error Message: CS0165: Use of unassigned local variable 'obj'

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• How few a files does it take to load a program on Linux?

  - by BCS

  The (hypothetical for now) situation is the user of my system is going to be given a chunk of C code and needs my system to compile and run it in a chroot sandbox that is generated on the fly and I want to require the fewest files in the box as possible. I'm only willing to play with compiler and linker settings (e.g. static link everything I can expect to be able to find) and make some moderate restriction on what the code can expect use (e.g. they can't use arbitrary libs). The question is how simple can I get the sandbox. Clearly I need the executable, but what about an ELF loader and a .so for the system calls? Can I dump either of them and is there something else I'll need?

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• Is it possible to come over the time out issue for a function call in C#?

  - by infant programmer

  In my program I call a method xslTransform.Load(strXmlQueryTransformPath, xslSettings, new XmlUrlResolver()); The problem I am facing is: sometimes this function doesn't execute well within the time. Sometimes compiler raises the time out issue after a long time of trial.. which inturn causes this part of application to shut. That is what I want to avoid. So if it exceeds certain time say 10 seconds I need to recall the method. Is it possible to add some code lines adjacent to this, which can meet the requirement?

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• Reducing Dimension For SVM in Sensor Network

  - by iinception

  Hi Everyone, I am looking for some suggestions on a problem that I am currently facing. I have a set of sensor say S1-S100 which is triggered when some event E1-E20 is performed. Assume, normally E1 triggers S1-S20, E2 triggers S15-S30, E3 triggers S20-s50 etc and E1-E20 are completely independent events. Occasionally an event E might trigger any other unrelated sensor. I am using ensemble of 20 svm to analyze each event separately. My features are sensor frequency F1-F100, number of times each sensor is triggered and few other related features. I am looking for a technique that can reduce the dimensionality of the sensor feature(F1-F100)/ or some techniques that encompasses all of the sensor and reduces the dimension too(i was looking for some information theory concept for last few days) . I dont think averaging, maximization is a good idea as I risk loosing information(it did not give me good result). Can somebody please suggest what am I missing here? A paper or some starting idea... Thanks in advance.

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• Design pattern: polymorphisim for list of objects

  - by ziang

  Suppose I have a class A, and A1, A2 inherits from A. There are 2 functions: List<A1> getListA1(){...} List<A2> getListA2(){...} Now I want to do something similar to both A1 and A2 in another function public void process(List<A>){...} If I want to pass the instance of either ListA1 or ListA2, of course the types doesn't match because the compiler doesn't allow the coercion from List< A1 to List< A. I can't do something like this: List<A1> listA1 = getListA1(); List<A> newList = (List<A>)listA1; //this is not allowed. So what is the best approach to the process()? Is there any way to do it in a universal way rather than write the similar code to both List and List?

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• Accessing subclass members from a superclass pointer C++

  - by Dr. Monkey

  I have an array of custom class Student objects. CourseStudent and ResearchStudent both inherit from Student, and all the instances of Student are one or the other of these. I have a function to go through the array, determine the subtype of each Student, then call subtype-specific member functions on them. The problem is, because these functions are not overloaded, they are not found in Student, so the compiler kicks up a fuss. If I have a pointer to Student, is there a way to get a pointer to the subtype of that Student? Would I need to make some sort of fake cast here to get around the compile-time error?

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• Scala: Mixing traits with private fields

  - by Vilius Normantas

  It's not much of a question, it's rather my excitement that it's possible at all! I wrote this little example just to prove the opposite - I expected either a compiler error or one of the values (111 or 222, I wasn't sure). scala> trait T1 { private val v = 111; def getValueT1 = v } scala> trait T2 { private val v = 222; def getValueT2 = v } scala> class T12 extends T1 with T2 scala> val t = new T12 scala> t.getValueT1 res9: Int = 111 scala> t.getValueT2 res10: Int = 222 Why doesn't the v get overridden? Off course this works only as long as vs are private, but still.

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