Search Results

Search found 9114 results on 365 pages for 'reversible functions'.

Page 233/365 | < Previous Page | 229 230 231 232 233 234 235 236 237 238 239 240  | Next Page >

• Restrict violation of architecture - asp.net MVP

  - by Srikanth

  If we had a defined hierarchy in an application. For ex a 3 - tier architecture, how do we restrict subsequent developers from violating the norms? For ex, in case of MVP (not asp.net MVC) architecture, the presenter should always bind the model and view. This helps in writing proper unit test programs. However, we had instances where people directly imported the model in view and called the functions violating the norms and hence the test cases couldn't be written properly. Is there a way we can restrict which classes are allowed to inherit from a set of classes? I am looking at various possibilities, including adopting a different design pattern, however a new approach should be worth the code change involved.

  Read the article

• use callback function to report stack backtrace

  - by user353394

  Assume I have the following: typedef struct { char *name; char binding; int address; } Fn_Symbol //definition of function symbol static Fn_Symbol *fnSymbols; //array of function symbols in a file statc int total; //number of symbol functions in the array and file static void PrintBacktrace(int sigum, siginfo_t * siginfo, void *context) { printf("\nSignal received %d (%s)\n", signum, strsignal(signum)); const int eip_index = 14; void *eip = (void *)((struct ucontext *)context)->uc_mcontext.gregs[eip_index]; printf("Error at [%p] %s (+0x%x), eip, fnName, offset from start); //????? exit(0); } I have this so far, but what is the best way using the fnSymbols static global pointer to identify the function where the error occured and then back trace through the stack to identify each calling function by address, name, and offset?

  Read the article

• Best practices for handling string in VC++?

  - by Hiren Gujarati

  As I am new to Visual C++, there are so many types for handling string. When I use some type and go ahead with coding but on next step, there are in-build functions that use other types & it always require to convert one type of string to other. I found so many blogs but so confused when see so many answers & try but some are working & some are not. Please give your answer or links that gives ultimate solution for handling different types of strings in visual c++.

  Read the article

• Registering a delegate function with an ISO C++ callback (on mono)

  - by Stick it to THE MAN

  I am thinking of wrapping ISO C++ code in C# class. The only problem so far is how to deal with the C++ callbacks. In .Net languages (C# and Vb.Net), I believe the callback equivalent. Sticking with C# for now, can anyone recommend a way that I can register the C# delegate functions with my ISO C++ code. The ISO C++ code is a notification library, and I want to be able to "push" the notifications to the mono framework (i.e. C# delegates in this case). My underlying assumption is that the mechanism/steps to implement this would be the same for the .Net languages - I'll just have to code the actual delegates in the .Net language of choice - is that assumption correct? Last but not the least, is the question of thread saftey. The underlying ISO C++ code that I am exposing to .Net (mono to be more specific), is both re-ntrant and thread safe - do I have to do anything "extra" to call .Net delegate from my ISO C++ code?

  Read the article

• Template type deduction with a non-copyable class

  - by Evan Teran

  Suppose I have an autolocker class which looks something like this: template <T> class autolocker { public: autolocker(T *l) : lock(l) { lock->lock(); } ~autolocker() { lock->unlock(); } private: autolocker(const autolocker&); autolocker& operator=(const autolocker&); private: T *lock; } Obviously the goal is to be able to use this autolocker with anything that has a lock/unlock method without resorting to virtual functions. Currently, it's simple enough to use like this: autolocker<some_lock_t> lock(&my_lock); // my_lock is of type "some_lock_t" but it is illegal to do: autolocker lock(&my_lock); // this would be ideal Is there anyway to get template type deduction to play nice with this (keep in my autolocker is non-copyable). Or is it just easiest to just specify the type?

  Read the article

• "Ambiguous template specialization" problem

  - by Setien

  I'm currently porting a heap of code that has previously only been compiled with Visual Studio 2008. In this code, there's an arrangement like this: template <typename T> T convert( const char * s ) { // slow catch-all std::istringstream is( s ); T ret; is >> ret; return ret; } template <> inline int convert<int>( const char * s ) { return (int)atoi( s ); } Generally, there are a lot of specializations of the templated function with different return types that are invoked like this: int i = convert<int>( szInt ); The problem is, that these template specializations result in "Ambiguous template specialization". If it was something besides the return type that differentiated these function specializations, I could obviously just use overloads, but that's not an option. How do I solve this without having to change all the places the convert functions are called?

  Read the article

• What does static linking against a library actually do?

  - by Salgar

  Say I had a library called libfoo which contained a class, a few static variables, possibly something with 'C' linkage, and a few other functions. Now I have a main program which looks like this: int main() { return 5+5; } When I compile and link this, I link against libfoo. Will this have any effect? Will my executable increase in size? If so, why? Do the static variables or their addresses get copied into my executable? Apologies if there is a similar question to this or if I'm being particularly stupid in any way.

  Read the article

• Style of if: to nest or not to nest

  - by Marco

  A colleague of mine and me had a discussion about the following best-practice issue. Most functions/methods start with some parameter checking. I advocate the following style, which avoids nesting. if (parameter one is ugly) return ERROR; if (parameter two is nonsense || it is raining) return ERROR; // do the useful stuff return result; He, who comes from a more functional/logic programming background, prefers the following, because it reduces the number of exit points from the function. if (parameter one is ok) { if (parameter two is ok && the sun is shining) { // do the useful stuff return result } } return ERROR; Which one would you prefer and why?

  Read the article

• correct way to store an exception in a variable

  - by Evan Teran

  I have an API which internally has some exceptions for error reporting. The basic structure is that it has a root exception object which inherits from std::exception, then it will throw some subclass of that. Since catching an exception thrown in one library and catching it in another can lead to undefined behavior (at least Qt complains about it and disallows it in many contexts). I would like to wrap the library calls in functions which will return a status code, and if an exception occurred, a copy of the exception object. What is the best way to store an exception (with it's polymorphic behavior) for later use? I believe that the c++0x futures API makes use of something like this. So what is the best approach? The best I can think of is to have a clone() method in each exception class which will return a pointer to an exception of the same type. But that's not very generic and doesn't deal with standard exceptions at all. Any thoughts?

  Read the article

• Best solution for language documentation.

  - by Simone Margaritelli

  I'm developing a new object oriented scripting language and the project itself is quite ready for audience now, so i'm starting to think about a serious (not as "drafty" as it is right now) way of document its grammar, functions from standard library and standard library classes. I've looked a bit around and almost every language hash its own web application for the documentation, Python uses Sphinx for instance. Which is the best PHP (don't have the time/will to install mod_who_knows_what on my server) application to accomplish this? I've used mediawiki a bit but i found its tag system a little bit hard to use in this context. Thanks for your answers.

  Read the article

• How to create a string array in matlab?

  - by aduric

  I would like to pass a vector of strings from C++ to matlab. I have tried using the functions available such as mxCreateCharMatrixFromStrings but it doesn't give me the correct behavior. So, I have something like this: void mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) { vector<string> stringVector; stringVector.push_back("string 1"); stringVector.push_back("string 2"); //etc... The problem is how do I get this vector to the matlab environment? plhs[0] = ??? My goal is to be able to run: >> [strings] = MyFunc(...) >> strings(1) = 'string 1'

  Read the article

• c++ Using const in a copy constructor?

  - by Anton

  I have never written copy constructor, so in order to avoid pain i wanted to know if what i have coded is legit. It compiles but i am not sure that it works as a copy constructor should. Also do i have to use const in the copy constructor or i can simply drop it. (What i dont like about const is that the compiler cries if i use some non const functions). //EditNode.h class EditNode { explicit EditNode(QString elementName); EditNode(const EditNode &src); } //EditNodeContainer.h class EditNodeContainer : public EditNode { explicit EditNodeContainer(QString elementName); EditNodeContainer(const EditNodeContainer &src); } //EditNodeContainer.cpp EditNodeContainer::EditNodeContainer(QString elementName):EditNode(elementName) { } //This seems to compile but not sure if it works EditNodeContainer::EditNodeContainer(const EditNodeContainer &src):EditNode(src) { } //the idea whould be to do something like this EditNodeContainer *container1 = new EditNodeContainer("c1"); EditNodeContainer *copyContainer = new EditNodeContainer(container1);

  Read the article

• Generating random numbers in C

  - by moonstruckhorrors

  While searching for Tutorials on generating random numbers in C I found This Topic When I try to use the rand() function with parameters, I always get the random number generated 0. When I try to use the rand() function with parameters, I always get the value 41. And whenever I try to use arc4random() and random() functions, I get a LNK2019 error. Here's what I'm doing: #include <stdlib.h> int main() { int x; x = rand(6); printf("%d", x); } This code always generate 41. Where am I going wrong?? P.S. : I'm running Windows XP SP3 and using VS2010 Command Prompt as compiler. P.P.S. : Took me 15 minutes to learn how to format properly.

  Read the article

• Is there a name for the technique of using base-2 numbers to encode a list of unique options?

  - by Lunatik

  Apologies for the rather vague nature of this question, I've never been taught programming and Google is rather useless to a self-help guy like me in this case as the key words are pretty ambiguous. I am writing a couple of functions that encode and decode a list of options into a Long so they can easily be passed around the application, you know this kind of thing: 1 - Apple 2 - Orange 4 - Banana 8 - Plum etc. In this case the number 11 would represent Apple, Orange & Plum. I've got it working but I see this used all the time so assume there is a common name for the technique, and no doubt all sorts of best practice and clever algorithms that are at the moment just out of my reach.

  Read the article

• Is there any Prototype Javascript function similar to Jquery Live to trace dynamic dom elements?

  - by Wbdvlpr

  Hi Event.observe(window,"load",function() { $$(".elem_classs").findAll(function(node){ return node.getAttribute('title'); }).each(function(node){ new Tooltip(node,node.title); node.removeAttribute("title"); }); }); Using above method, I can retrieve all elements having ".elem_class" and apply some javascript functions on them. But I have a modal/popup box which has some elements also having ".elem_class" and these dont get in the scope of findAll/each as they are loaded into the dom thru ajax. How do I apply the same to dynamically loaded elements as well? I am using Prototype Library. (I have used JQuery's Live function which keeps track of all future elements, but need to achieve something similar using Prototype) Thanks.

  Read the article

• Webservice and ORM Framework?

  - by Sebastian

  Does anybody know a good web framework that includes an ORM mapper and allows straight forward implementation of web services? I'm looking for a framework written in PHP or C++. I'm looking for the following features (not all of them required, some will do nicely) data definition in one place used by database and web service WSDL generation XML output/JSON output boilerplate code generation So what I would like is a framework that let's me specify the objects, the web service functions on those objects and then generate everything that is required leaving me to fill the business logic (connecting the database to the web service). Anything like that out there? Background information for why I need this: I'm looking into creating a web project: the client is a rich web application that fetches all its data using AJAX. It will be completely custom made using only a low level javascript library. The server back end is supposed to serve static content and javascript (basically the rich web application) and to provide a RESTful web service API (which I would like to implement using aforementioned framework).

  Read the article

• Functional languages & support for memoization

  - by Joel

  Do any of the current crop of popular functional languages have good support for memoization & if I was to pick one on the strength of its memoisation which would you recommend & why? Update: I'm looking to optimise a directed graph (where nodes could be functions or data). When a node in the graph is updated I would like the values of other nodes to be recalculated only if they depend the node that changed. Update2: require free or open-source language/runtime.

  Read the article

• Can I make valgrind ignore glibc libraries?

  - by Jack

  Is it possible to tell valgrind to ignore some set of libraries? Specifically glibc libraries.. Actual Problem: I have some code that runs fine in normal execution. No leaks etc. When I try to run it through valgrind, I get core dumps and program restarts/stops. Core usually points to glibc functions (usually fseek, mutex etc). I understand that there might be some issue with incompatible glibc / valgrind version. I tried various valgrind releases and glibc versions but no luck. Any suggestions?

  Read the article

• Other SecurityManager implementations available?

  - by mhaller

  Is there any other implementation (e.g. in an OSS project) of a Java SecurityManager available which has more features than the one in the JDK? I'm looking for features like configurable at runtime policies updateable at runtime, read from other data sources than a security.policy file Thread-aware, e.g. different policies per Thread Higher-level policies, e.g. "Disable network functions, but allow JDBC traffic" Common predefined policies, e.g. "Allow read-access to usual system properties like file.encoding or line.separator, but disallow read-access to user.home" Monitoring and audit trace logging, e.g. "Log all file access, log all network access going NOT to knownhost.example.org" Blocking jobs "requesting" a permission until an administrator grants permission, letting the thread/job continue ... I'm pretty sure that application servers (at least the commercial ones) have their own SecurityManager implementation or at least their own policy configuration. I'm wondering if there is any free project with similar requirements.

  Read the article

• Should I use implicit conversions to enforce preconditions?

  - by Malvolio

  It occurs to me that I could use use implicit conversions to both announce and enforce preconditions. Consider this: object NonNegativeDouble { implicit def int2nnd(d : Double) : NonNegativeDouble = new NonNegativeDouble(d) implicit def nnd2int(d : NonNegativeDouble) : Double = d.v def sqrt(n : NonNegativeDouble) : NonNegativeDouble = scala.math.sqrt(n) } class NonNegativeDouble(val v : Double ) { if (v < 0) { throw new IllegalArgumentException("negative value") } } object Test { def t1 = { val d : Double = NonNegativeDouble.sqrt(3.0); printf("%f\n", d); val n : Double = NonNegativeDouble.sqrt(-3.0); } } Ignore for the moment the actual vacuity of the example: my point is, the subclass NonNegativeDouble expresses the notion that a function only takes a subset of the entire range of the class's values. First is this: A good idea, a bad idea, or an obvious idea everybody else already knows about Second, this would be most useful with basic types, like Int and String. Those classes are final, of course, so is there a good way to not only use the restricted type in functions (that's what the second implicit is for) but also delegate to all methods on the underlying value (short of hand-implementing every delegation)?

  Read the article

• Why not speed up testing by using function dependency graph?

  - by Maltrap

  It seems logical to me that if you have a dependency graph of your source code (tree showing call stack of all functions in your code base) you should be able to save a tremendous amount of time doing functional and integration tests after each release. Essentially you will be able to tell the testers exactly what functionality to test as the rest of the features remain unchanged from a source code point of view. If for instance you change a spelling mistake in once piece of the code, there is no reason to run through your whole test script again "just in case" you introduced a critical bug. My question, why are dependency trees not used in software engineering and if you use them, how do you maintain them? What tools are available that generate these trees for C# .NET, C++ and C source code?

  Read the article

• Javascript / Flash : When exactly are flash external callback methods triggered ?

  - by felace

  I have a flash application using callbacks to javascript functions (eg. when it receives some data over a socket, it'll call a js script which would change the content of a div according to that given data). Afaik, there is no actual mutual exclusion in javascript so I'm not sure if I can/need to simulate something like : callbackFunc() { lock(mutex1) foo unlock(mutex1) } ... someOtherFunc() { lock(mutex1) bar unlock(mutex1) } So, the question is, when are those callbacks called ? Are they simply queued to be executed right after the browser finishes its task or are they triggered randomly ?

  Read the article

• How to integrate access control with my ORM in a .net windows form application?

  - by Ying

  I am developing a general database query tools, a .Net 3.5 Windows Form application. In order to make the presentation layer is independent of the database layer. I use an ORM framework, XPO from DevExpress. But, I have no access control function built in. I surfed Internet and I found in WCF Data Services, there is an interesting concept, Interceptor, which is following AOP(Aspect Oriented Programming). I am wondering who has such an experience to build access control in ORM. My basic requirement is : It should be a general method and controlled by users in runtime. So any hard coding is not acceptable. It could be based on attribute, database table, or even an external assembly. I am willing to buy a ready solution. According to the idea of AOP, an access control function can be integrated with existing functions easily and nearly not knowingly to the previous developer;) Any suggestions are welcome.

  Read the article

• Why the macros in Objective-C / Cocoa?

  - by Joe

  I'm coming from a place without macros (Java/Python/C#/Scala) so perhaps my perspective is distorted but... Why are macros used in Cocoa? Two that spring to mind are NSLocalizedString and NSAssert (and STAssert). Would it be so hard / unsuitable to make them functions (which could be inlined)? I suppose I find them a little bizarre as an unnecessary throw-back to C (and yes, I am familiar with the pedigree of Obj-C). Is it just something that was done back in the day or is there a specific reason?

  Read the article

• How to inline a function for only release build.

  - by Benjamin

  // common.h // This is foo funtion. It has a body. __inline void foo() { /* something */ } // a.cpp #include "common.h" // for foo function // Call foo // b.cpp #include "common.h" // for foo function // Call foo I would like to inline the foo function only when I build for release. -I dont want to inline functions for Debug build. I tried it but linker errors annoyed me. In this case, foo function's body is defined in common.h header file. so if I just do //common.h #if !defined(_DEBUG) __inline #endif void foo() { /* something */ } I will be met a link error in DEBUG build. Because two modules try to include common.h. I have no idea to solve it. Is it possible?

  Read the article

< Previous Page | 229 230 231 232 233 234 235 236 237 238 239 240  | Next Page >