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  • Convert "this" to a reference-to-pointer

    - by Austin Hyde
    Just stumbled onto this problem. (title says it all) Let's say I have a struct struct Foo { void bar () { do_baz(this); } void do_baz(Foo*& pFoo) { pFoo->p_sub_foo = new Foo; // for example } Foo* p_sub_foo; } GCC tells me that temp.cpp: In member function ‘void Foo::bar()’: temp.cpp:3: error: no matching function for call to ‘Foo::do_baz(Foo* const)’ temp.cpp:5: note: candidates are: void Foo::do_baz(Foo*&) So, how do I convert what is apparently a const Foo* to a Foo*&?

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  • how to fix: ctags null expansion of name pattern "\1"

    - by bua
    Hi, As the title points I have problem with ctags when trying to parse user-defined language. Basically I've followed those instructions. The quickest and easiest way to do this is by defining a new language using the program options. In order to have Swine support available every time I start ctags, I will place the following lines into the file $HOME/.ctags, which is read in every time ctags starts: --langdef=swine --langmap=swine:.swn --regex-swine=/^def[ \t]*([a-zA-Z0-9_]+)/\1/d,definition/ The first line defines the new language, the second maps a file extension to it, and the third defines a regular expression to identify a language definition and generate a tag file entry for it. I've tried different flags: b,e for regex. My definition of tag is: --regex-q=/^[ \t]*[^[:space:]]*[:space:]*:[:space:]*{/\l/f,function/b When I replace \1 with anything else (ascii caracter set ), It works. the output is: (--regex-q=/^[ \t]*[^[:space:]]*[:space:]*:[:space:]*{/my function name/f,function/b) !_TAG_FILE_FORMAT 2 /extended format; --format=1 will not append ;" to lines/ !_TAG_FILE_SORTED 1 /0=unsorted, 1=sorted, 2=foldcase/ !_TAG_PROGRAM_AUTHOR Darren Hiebert /[email protected]/ !_TAG_PROGRAM_NAME Exuberant Ctags // !_TAG_PROGRAM_URL http://ctags.sourceforge.net /official site/ !_TAG_PROGRAM_VERSION 5.8 // my function name file.q /^.ras.getLocation:{[u]$/;" f my function name file.q /^.a.getResource:{[u; pass]$/;" f my function name file.q /^.a.init:{$/;" f my function name file.q /^.a.kill:{[u; force]$/;" f my function name file.q /^.asdf.status:{[what; u]$/;" f my function name file.q /^.pc:{$/;" f Why \1 doesn't work? (I've tried all 1-9)

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  • Is writing a reference atomic on 64bit VMs

    - by Steffen Heil
    Hi The java memory model mandates that writing a int is atomic: That is, if you write a value to it (consisting of 4 bytes) in one thread and read it in another, you will get all bytes or none, but never 2 new bytes and 2 old bytes or such. This is not guaranteed for long. Here, writing 0x1122334455667788 to a variable holding 0 before could result in another thread reading 0x112233440000000 or 0x0000000055667788. Now the specification does not mandate object references to be either int or long-sized. For type safety reasons I suspect they are guaranteed to be written atomiacally, but on a 64bit VM these references could be very well 64bit values (merely memory addresses). No here are my question: Are there any memory model specs covering this (that I haven't found)? Are long-writes suspect to be atomic on 64bit VMs? Are VMs forced to map references to 32bit? Regards, Steffen

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  • How to get child container reference in View Model

    - by niels-verkaart
    Hello, I´m trying to share a Data Service (Entity Manager) wrapped in a Repository from a ViewModel (called 'AVM') in Module A to a ViewModel (called 'BVM') in Module B, and I can't get this working. We use PRISM/Unity 2.0 This is my scenario: A user may open multiple Customer screens (composite view as mini shell) each with another customer (unit of work). We realize this using child containers. Each child container resolves it's own repository with its own Entity manager (the repository is a singleton within the child container). This is done in module A. The main shell has a main region manager, and each Customer screen with its childcontainer creates a scoped region. In each customer screen there is a View 'AV' (connected to ViewModel 'AVM') with a SubRegion (tab control) registered as 'SubRegion'. We create this with a 'Screen Factory' In Module B we have a Customer Orders in View 'BV' and ViewModel 'BVM'. In the constructor of Module B we get the main container by injection. In the initialize method we resolve the (main) region manager and register View 'BV' with it. In the constructor of View 'BV' a ViewModel 'BVM' is injected/created. Now this works, but the ViewModel 'BVM' cannot get the child container. It only get the main container. Is this doable, or do I have to do this another way? Thanks, Niels

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  • Handy F# snippets

    - by Benjol
    There are already two questions about F#/functional snippets. However what I'm looking for here are useful snippets, little 'helper' functions that are reusable. Or obscure but nifty patterns that you can never quite remember. Something like: open System.IO let rec visitor dir filter= seq { yield! Directory.GetFiles(dir, filter) for subdir in Directory.GetDirectories(dir) do yield! visitor subdir filter} I'd like to make this a kind of handy reference page. As such there will be no right answer, but hopefully lots of good ones.

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  • No compile errors when reference added, but errors seen upon build

    - by cjs
    A solution was just converted from VS 2008 to VS 2010. My VS 2010 build is failing with the popular "The type or namespace X could not be found". When I go to the project and go to Add References and add the appropriate project dll, the class name appears in blue text as if .NET found the correct class. However, when I go to the Build menu and select "Build Solution" I get the "namespace not found error" and the class name is no longer blue. Thanks.

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  • Cross Thread Exception in PropertyChangedEvent in WPF

    - by Ashish Ashu
    I have a ListView that is binded to my custom collection. At run time , I am updating the certain properties of my entity in my custom collection in my ViewModel. At the same time , I am also doing the custom sorting in the listview. The custom sorting is applicable when I click on the any column header of the listview. For example, I am updating the current datetime on my entity on every 5 seconds and simulaneously , I am applying custom sorting based on DateTime. (The Listview is third party control). Hence I am doing two operations on my custom collection at the same time. Should I pass the dispatcher of my control in the view model and call any methods ( which updates any entity in my custom collection ) through UI dispatcher ?

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  • Alternative Python standard library reference

    - by Ender
    I love Python; I absolutely despise its official documentation. Tutorials do not count as library references, but that appears to be what they're attempting. What I really want is the ability to find a class in the standard library and view documentation for all of its properties and methods. Actionscript, MSDN, and Java all do this just fine (although each with their odd quirks). Where is this for python? For example, I wanted to sort a list. mylist.sort(). Awesome. But what if I wanted it sorted in descending order? Official documentation is not - much - help. Or what if I wanted to specify a key function? That's also supported: mylist.sort(key=lamba item: item.customVar)- but documented...where? I understand that Python's approach to OOP may not be equivalent to Java et. al. Maybe list isn't actually a class - maybe it's just a function that returns an iterable when the tachyon beams are set to glorious and the unboxed hyper enumeration is quantized, but...I don't care. I just want to know how to sort lists. (Apologies for the angst - too much caffeine today)

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  • How to protect code from crashes in this situation

    - by Davit Siradeghyan
    int arr[ 5 ] = { 0 }; int i = 8; // out of bounds arr[ i ] = 8; I know that I can just check i like this if( i < 0 || i 5 ) .... I also know about SEH in Visual Studio, but it looks like not working solution. __try { /* code */ } __except(GetExceptionCode() == EXCEPTION_ARRAY_BOUNDS_EXCEEDED) This is not working. As I see SEH working in situations like divide to 0, access protected pages ... How can I protect my program from crashes?

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  • unhandeled exception occured in c#

    - by abid
    hey. i`m getting this error that system.data.datarowview is not permitted in this contexxt. valid expressions are constants expressions and ( in some contexts). column name are not permitted.. can any body guide me what this error says.. can any one provide me a suggestion whether where im wrong.. any guesses guys??? im not getting it.. :/

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  • view to select specific period or latest when null

    - by edosoft
    Hi I have a product table which simplifies to this: create table product(id int primary key identity, productid int, year int, quarter int, price money) and some sample data: insert into product select 11, 2010, 1, 1.11 insert into product select 11, 2010, 2, 2.11 insert into product select 11, 2010, 3, 3.11 insert into product select 12, 2010, 1, 1.12 insert into product select 12, 2010, 2, 2.12 insert into product select 13, 2010, 1, 1.13 Prices are can be changed each quarter, but not all products get a new price each quarter. Now I could duplicate the data each quarter, keeping the price the same, but I'd rather use a view. How can I create a view that can be used to return prices for (for example) quarter 2? I've written this to return the current (=latest) price: CREATE VIEW vwCurrentPrices AS SELECT * FROM ( SELECT *, ROW_NUMBER() OVER (PARTITION BY productid ORDER BY year DESC, quarter DESC) AS Ranking FROM product ) p WHERE p.Ranking = 1 I'd like to create a view so I can use queries like select * from vwProduct where quarter = 2

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  • Obtaining Excel worksheet reference by worksheet name via C#

    - by Chapax
    Hi, I'm currently obtaining a handle to a Excel worksheet by using the below C# code: *Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(15);//Get the worksheet "SubSignOff" number* Is there any way that I can obtain the same by using the worksheet name -- "SubSignOff" ? Many thanks for your help. --Chapax

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  • Python Pre-testing for exceptions when coverage fails

    - by Tal Weiss
    I recently came across a simple but nasty bug. I had a list and I wanted to find the smallest member in it. I used Python's built-in min(). Everything worked great until in some strange scenario the list was empty (due to strange user input I could not have anticipated). My application crashed with a ValueError (BTW - not documented in the official docs). I have very extensive unit tests and I regularly check coverage to avoid surprises like this. I also use Pylint (everything is integrated in PyDev) and I never ignore warnings, yet I failed to catch this bug before my users did. Is there anything I can change in my methodology to avoid these kind of runtime errors? (which would have been caught at compile time in Java / C#?). I'm looking for something more than wrapping my code with a big try-except. What else can I do? How many other build in Python functions are hiding nasty surprises like this???

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  • "EXC_BAD_ACCESS: Unable to restore previously selected frame" Error, Array size?

    - by Job
    Hi there, I have an algorithm for creating the sieve of Eratosthenes and pulling primes from it. It lets you enter a max value for the sieve and the algorithm gives you the primes below that value and stores these in a c-style array. Problem: Everything works fine with values up to 500.000, however when I enter a large value -while running- it gives me the following error message in xcode: Program received signal: “EXC_BAD_ACCESS”. warning: Unable to restore previously selected frame. Data Formatters temporarily unavailable, will re-try after a 'continue'. (Not safe to call dlopen at this time.) My first idea was that I didn't use large enough variables, but as I am using 'unsigned long long int', this should not be the problem. Also the debugger points me to a point in my code where a point in the array get assigned a value. Therefore I wonder is there a maximum limit to an array? If yes: should I use NSArray instead? If no, then what is causing this error based on this information? EDIT: This is what the code looks like (it's not complete, for it fails at the last line posted). I'm using garbage collection. /*--------------------------SET UP--------------------------*/ unsigned long long int upperLimit = 550000; // unsigned long long int sieve[upperLimit]; unsigned long long int primes[upperLimit]; unsigned long long int indexCEX; unsigned long long int primesCounter = 0; // Fill sieve with 2 to upperLimit for(unsigned long long int indexA = 0; indexA < upperLimit-1; ++indexA) { sieve[indexA] = indexA+2; } unsigned long long int prime = 2; /*-------------------------CHECK & FIND----------------------------*/ while(!((prime*prime) > upperLimit)) { //check off all multiples of prime for(unsigned long long int indexB = prime-2; indexB < upperLimit-1; ++indexB) { // Multiple of prime = 0 if(sieve[indexB] != 0) { if(sieve[indexB] % prime == 0) { sieve[indexB] = 0; } } } /*---------------- Search for next prime ---------------*/ // index of current prime + 1 unsigned long long int indexC = prime - 1; while(sieve[indexC] == 0) { ++indexC; } prime = sieve[indexC]; // Store prime in primes[] primes[primesCounter] = prime; // This is where the code fails if upperLimit > 500000 ++primesCounter; indexCEX = indexC + 1; } As you may or may not see, is that I am -very much- a beginner. Any other suggestions are welcome of course :)

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  • CodeContracts: ccrewrite fails with Object reference not set to an instance of an object

    - by Vyas Bharghava
    The below code makes ccrewrite blow up! Ideas? BTW, If you comment out the ActualClass, ccrewrite succeeds... [ContractClass(typeof(TestContracts))] interface ITestInterface { bool IsStarted { get; set; } void Begin(); } class ActualClass : ITestInterface { public bool IsStarted { get; set; } public void Begin() { this.IsStarted = true; } } [ContractClassFor(typeof(ITestInterface))] class TestContracts : ITestInterface { ITestInterface Current { get; set; } private TestContracts() { Current = this; } #region ITestInterface Members bool ITestInterface.IsStarted { get; set; } void ITestInterface.Begin() { Contract.Requires(!Current.IsStarted); Contract.Ensures(Current.IsStarted); } Thanks in advance!

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  • Check if the internet cannot be accessed in Python

    - by Sridhar Ratnakumar
    I have an app that makes a HTTP GET request to a particular URL on the internet. But when the network is down (say, no public wifi - or my ISP is down, or some such thing), I get the following traceback at urllib.urlopen: 70, in get u = urllib2.urlopen(req) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/urllib2.py", line 126, in urlopen return _opener.open(url, data, timeout) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/urllib2.py", line 391, in open response = self._open(req, data) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/urllib2.py", line 409, in _open '_open', req) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/urllib2.py", line 369, in _call_chain result = func(*args) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/urllib2.py", line 1161, in http_open return self.do_open(httplib.HTTPConnection, req) File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/urllib2.py", line 1136, in do_open raise URLError(err) URLError: <urlopen error [Errno 8] nodename nor servname provided, or not known> I want to print a friendly error to the user telling him that his network maybe down instead of this unfriendly "nodename nor servname provided" error message. Sure I can catch URLError, but that would catch every url error, not just the one related to network downtime. I am not a purist, so even an error message like "The server example.com cannot be reached; either the server is indeed having problems or your network connection is down" would be nice. How do I go about selectively catching such errors? (For a start, if DNS resolution fails at urllib.urlopen, that can be reasonably assumed as network inaccessibility? If so, how do I "catch" it in the except block?)

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  • ExecutionEngineException thrown when loading native dll in c#

    - by Axarydax
    Hi there. I have a 32-bit .net application that uses a native 32-bit DLL via DllImport(). The native DLL is our internal file analysis library, and I need to use it as porting it to C# would be a problem if people update it (other software uses it). The problem is that when I try to execute any method in the native DLL I get a System.ExecutionEngineException thrown. In fact, I've reduced the managed application to a simple tester that just calls a native method, but it still fails. I am on 64-bit Windows 7, but that should not matter as I'm compiling everything as 32-bit binaries. What is also interesting, when I look at the native DLL in the Dependency Walker, it shows that it can't find msvcr90.dll - but when I open any other of our native DLLs in the Dependency Walker, it can find their referenced msvcr90.dll just fine. Can there by some wrongness in the compilation of native DLL that messss up its DLL references?

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  • Invalid Cast Exception in ASP.NET but not in WinForms

    - by Shadow Scorpion
    I have a problem in this code: public static T[] GetExtras <T>(Type[] Types) { List<T> Res = new List<T>(); foreach (object Current in GetExtras(typeof(T), Types)) { Res.Add((T)Current);//this is the error } return Res.ToArray(); } public static object[] GetExtras(Type ExtraType, Type[] Types) { lock (ExtraType) { if (!ExtraType.IsInterface) return new object[] { }; List<object> Res = new List<object>(); bool found = false; found = (ExtraType == typeof(IExtra)); foreach (Type CurInterFace in ExtraType.GetInterfaces()) { if (found = (CurInterFace == typeof(IExtra))) break; } if (!found) return new object[] { }; foreach (Type CurType in Types) { found = false; if (!CurType.IsClass) continue; foreach (Type CurInterface in CurType.GetInterfaces()) { try { if (found = (CurInterface.FullName == ExtraType.FullName)) break; } catch { } } try { if (found) Res.Add(Activator.CreateInstance(CurType)); } catch { } } return Res.ToArray(); } } When I'm using this code in windows application it works! But I cant use it on ASP page. Why?

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  • .NET Debugging - System.Threading.ExecutionContext.runTryCode

    - by moogs
    We have this bug that only appears 30% of the time for the Release build. Opening the crash dump in WinDbg (snipped "!analyze -v" output): FAULTING_IP: +4 00000000`00000004 ?? ??? EXCEPTION_RECORD: ffffffffffffffff -- (.exr 0xffffffffffffffff) ExceptionAddress: 0000000000000004 ExceptionCode: c0000005 (Access violation) ExceptionFlags: 00000000 NumberParameters: 2 Parameter[0]: 0000000000000008 Parameter[1]: 0000000000000004 Attempt to execute non-executable address 0000000000000004 ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s. WRITE_ADDRESS: 0000000000000004 MANAGED_STACK: (TransitionMU) 0000000024B9E370 000007FEEDA1DD38 mscorlib_ni!System.Threading.ExecutionContext.runTryCode(System.Object)+0x178 (TransitionUM) (TransitionMU) 0000000024B9DFB0 000007FF00439010 MyLibrary!DocInfo.IsStatusOK()+0x30 Now, IsStatusOK() just calls PrintSystemJobInfo.Get(), but that doesn't seem to even appear in the stack. Any ideas on how to debug this? I'm sure runTryCode() is really not the problem...but..I'm stuck. Thanks! (I'm really groping here).

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  • Class Self-Reference

    - by Free Bullets
    I have the following code. The angle function needs some information from the class it was called from. What's the best way to do this? class MyScannedRobotEvent extends robocode.ScannedRobotEvent { public int angle(robocode.Robot myRobot) { return (int) Math.toRadians((myRobot.getHeading() + getBearing()) % 360); } } public class MyRobot extends robocode.Robot { int a = angle(**WHATDOIPUTHERE?**) }

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  • Reference a internal class from a Windows Workflow Activity

    - by Ben Hughes
    I'm creating a custom Workflow activity for use within TFS2010. In the same assembly I have a XAML activity and a C# code activity. The XAML activity references the code activity. When the assembly is deployed to our clients, I only want them to be able to use the Workflow activity. The code activity is of little use by itself and would no doubt confuse them. I thought the logical way to do this would be to set the code activity class to internal: the XAML is in the same assembly and should be able to access it. However, when I do that I get an error in the XAML saying that the assembly can't be found. Is there a way to make activities internal/hidden?

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  • Reference inherited class's <T>ype in a derived class

    - by DRapp
    I don't know if its possible or not, but here's what I need. I'm toying around with something and want to know if its possible since you can't create your own data type based on a sealed type such as int, Int32, Int64, etc. I want to create a top-level class that is defined of a given type with some common stuff. Then, derive this into two subclasses, but in this case, each class is based on either and int or Int64 type. From THAT instance, create an instance of either one and know its yped basis for parameter referenc / return settings. So when I need to create an instance of the "ThisClass", I don't have to know its type basis of either int or Int64, yet IT will know the type and be able to allow methods/functions to be called with the typed... This way, If I want to change my ThisClass definition from SubLevel1 to SubLevel2, I don't have to dance around all different data type definitions. Hope this makes sense.. public class TopLevel<T> { ... } pubic class SubLevel1 : TopLevel<int> { ... } public class SubLevel2 : TopLevel<Int64> { ... } public class ThisClass : SubLevel1 { ... public <based on the Int data type from SubLevel1> SomeFunc() { return <the Int value computed>; } }

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