Search Results

Search found 54446 results on 2178 pages for 'struct vs class'.

Page 722/2178 | < Previous Page | 718 719 720 721 722 723 724 725 726 727 728 729  | Next Page >

  • update attribute a element in arraylist on java ?

    - by tiendv
    I have a class Class TextChunks extends Token { ArrayList<Token> arrt = new ArrayList<Token>(); } extent fron class : class Token { String s; int frequency = 1 ;// Tern frequency in TextChunk } Now in token i have arraylist token , i want to update attribute frequency of token in Texchunks when have more than one tokens same . For clearly a give a example : Texchunks :" in particular in domain and range in some " So have 8 token : in,particular,in,domain,and,range,in,some i want update attribute frequency for token : in this example when i get attribute frequency of token "in" must return 3 it mean when i call : get frequency of Texchunks when dislay : in 3 particular 1 in 3 domain 1 and 1 range 1 in 3 some 1 here my code : public TextChunks updateFrequencyOfTokenInTextChunks (TextChunks tc) throws CloneNotSupportedException { TextChunks result = (TextChunks) tc.clone(); for (int i =0 ; i< result.arrt.size() ; i++ ){ int j=i+1; if (result.arrt.get(i).compareTwoToken(result.arrt.get(j))== true ) { // help here how to update attribute result.arrt.get(i) // and result.arrt.get(J) = ++ and } } return tc; } Thanks in advandce

    Read the article

  • Getting JQuery UI Sortable to work on asp.net ListView items?

    - by Xaisoft
    I have the following ListView in which I am using the JQuery UI sortable function to be able to sort the items in the ListView. The problem is that I can't put a sortable class on the table in the ItemTemplate because it does not work, if I put a class="sortable" on the outer div, it works, but it allows me to sort everything within the ListView, I just want to be able to move sort the tables. Here is the markup <div> //Works here, but hr's become sortable too. <asp:ListView ID="lvwDocuments" runat="server"> <LayoutTemplate> <h3> Documents</h3> <asp:PlaceHolder ID="itemPlaceHolder" runat="server"> </asp:PlaceHolder> </LayoutTemplate> <ItemTemplate> <table class="sortable"> //Does not work Here <tr> <td> <p class="title"> <a runat="server" href='<%#Eval("url") %>'> <%#Eval("title") %></a></p> <br /> <p> <%#Eval("description") %></p> </td> </tr> </table> </ItemTemplate> <ItemSeparatorTemplate> <hr /> </ItemSeparatorTemplate> </div> Also, How can I preserve the sort order even after the page is refreshed.

    Read the article

  • SimpleTest assertTags - loose matching? (for CakePHP)

    - by Arkaaito
    I'd like to use SimpleTest to set up some functionality tests for our project - in particular, we have a very busy page which has some random components and some static components, and I'd like to be able to write a simple test which only confirms the static bits (preferably only the one or two most important ones). In other words, I want to be able to leave out any tags on the page I don't care about, and write something like: $result = "<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><title>...</title><meta .../></head><body><script type="text/javascript">...</script><div class="center-splash"><span>Welcome JohnDoe</span><p>Your progress:</p>...</div><div class="left-column">...</div><div class="right-column">...</div>...</body></html>"; $expects = array('html'=>true,'body'=>true,'div'=>array('class'=>'center_splash'),'span'=>true,'Welcome JohnDoe','/span','/div','/body','/html'); $this->assertTagsButIgnoreExtras($result, $expects); When I try this with assertTags it fails. Is there a version of assertTags which allows this - something either officially part of the SimpleTest or CakePHP project or unofficially put out under the MIT license or similar?

    Read the article

  • Unit Testing Interfaces in Python

    - by Nicholas Mancuso
    I am currently learning python in preperation for a class over the summer and have gotten started by implementing different types of heaps and priority based data structures. I began to write a unit test suite for the project but ran into difficulties into creating a generic unit test that only tests the interface and is oblivious of the actual implementation. I am wondering if it is possible to do something like this.. suite = HeapTestSuite(BinaryHeap()) suite.run() suite = HeapTestSuite(BinomialHeap()) suite.run() What I am currently doing just feels... wrong (multiple inheritance? ACK!).. class TestHeap: def reset_heap(self): self.heap = None def test_insert(self): self.reset_heap() #test that insert doesnt throw an exception... for x in self.inseq: self.heap.insert(x) def test_delete(self): #assert we get the first value we put in self.reset_heap() self.heap.insert(5) self.assertEquals(5, self.heap.delete_min()) #harder test. put in sequence in and check that it comes out right self.reset_heap() for x in self.inseq: self.heap.insert(x) for x in xrange(len(self.inseq)): val = self.heap.delete_min() self.assertEquals(val, x) class BinaryHeapTest(TestHeap, unittest.TestCase): def setUp(self): self.inseq = range(99, -1, -1) self.heap = BinaryHeap() def reset_heap(self): self.heap = BinaryHeap() class BinomialHeapTest(TestHeap, unittest.TestCase): def setUp(self): self.inseq = range(99, -1, -1) self.heap = BinomialHeap() def reset_heap(self): self.heap = BinomialHeap() if __name__ == '__main__': unittest.main()

    Read the article

  • Databinding to the DataGridView (Enums + Collections)

    - by Ian
    I'm after a little help with the techniques to use for Databinding. It's been quite a while since I used any proper data binding and want to try and do something with the DataGridView. I'm trying to configure as much as possible so that I can simply designed the DatagridView through the form editor, and then use a custom class that exposes all my information. The sort of information I've got is as follows: public class Result { public String Name { get; set; } public Boolean PK { get; set; } public MyEnum EnumValue { get; set; } public IList<ResultInfos> { get; set; } } public class ResultInfos { get; set; } { public class Name { get; set; } public Int Value { get; set; } public override String ToString() { return Name + " : " Value.ToString(); } } I can bind to the simple information without any problem. I want to bind to the EnumValue with a DataGridViewComboBoxColumn, but when I set the DataPropertyName I get exceptions saying the enum values aren't valid. Then comes the ResultInfo collection. Currently I can't figure out how to bind to this and display my items, again really I want this to be a combobox, where the 1st Item is selected. Anyone any suggestions on what I'm doing wrong? Thanks

    Read the article

  • Generics in a bidirectional association

    - by Verhoevenv
    Let's say I have two classes A and B, with B a subtype of A. This is only part of a richer type hierarchy, obviously, but I don't think that's relevant. Assume A is the root of the hierarchy. There is a collection class C that keeps track of a list of A's. However, I want to make C generic, so that it is possible to make an instance that only keeps B's and won't accept A's. class A(val c: C[A]) { c.addEntry(this) } class B(c: C[A]) extends A(c) class C[T <: A]{ val entries = new ArrayBuffer[T]() def addEntry(e: T) { entries += e } } object Generic { def main(args : Array[String]) { val c = new C[B]() new B(c) } } The code above obviously give the error 'type mismatch: found C[B], required C[A]' on the new B(c) line. I'm not sure how this can be fixed. It's not possible to make C covariant in T (like C[+T <: A]) because the ArrayBuffer is non-variantly typed in T. It's not possible to make the constructor of B require a C[B] because C can't be covariant. Am I barking up the wrong tree here? I'm a complete Scala newbie, so any ideas and tips might be helpful. Thank you! EDIT: Basically, what I'd like to have is that the compiler accepts both val c = new C[B]() new B(c) and val c = new C[A]() new B(c) but would reject val c = new C[B]() new A(c) It's probably possible to relax the typing of the ArrayBuffer in C to be A instead of T, and thus in the addEntry method as well, if that helps.

    Read the article

  • How do I handle freeing unmanaged structures on application close?

    - by LostKaleb
    I have a C# project in which i use several unmanaged C++ functions. More so, I also have static IntPtr that I use as parameters for those functions. I know that whenever I use them, I should implement IDisposable in that class and use a destructor to invoke the Dispose method, where I free the used IntPtr, as is said in the MSDN page. public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } private void Dispose(bool disposing) { // Check to see if Dispose has already been called. if (!this.disposed) { if (disposing) { component.Dispose(); } CloseHandle(m_InstanceHandle); m_InstanceHandle = IntPtr.Zero; disposed = true; } } [System.Runtime.InteropServices.DllImport("Kernel32")] private extern static Boolean CloseHandle(IntPtr handle); However, when I terminate the application, I'm still left with a hanging process in TaskManager. I believe that it must be related to the used of the MarshalAs instruction in my structures: [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] public struct SipxAudioCodec { [MarshalAs(UnmanagedType.ByValTStr, SizeConst=32)] public string CodecName; public SipxAudioBandwidth Bandwidth; public int PayloadType; } When I create such a structure should I also be careful to free the space it allocs using a destructor? [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] public struct SipxAudioCodec { [MarshalAs(UnmanagedType.ByValTStr, SizeConst=32)] public string CodecName; public SipxAudioBandwidth Bandwidth; public int PayloadType; ~SipxAudioCodec() { Marshal.FreeGlobal(something...); } }

    Read the article

  • DCI: How to implement Context with Dependency Injection?

    - by ciscoheat
    Most examples of a DCI Context are implemented as a Command pattern. When using Dependency Injection though, it's useful to have the dependencies injected in the constructor and send the parameters into the executing method. Compare the Command pattern class: public class SomeContext { private readonly SomeRole _someRole; private readonly IRepository<User> _userRepository; // Everything goes into the constructor for a true encapsuled command. public SomeContext(SomeRole someRole, IRepository<User> userRepository) { _someRole = someRole; _userRepository = userRepository; } public void Execute() { _someRole.DoStuff(_userRepository); } } With the Dependency injected class: public class SomeContext { private readonly IRepository<User> _userRepository; // Only what can be injected using the DI provider. public SomeContext(IRepository<User> userRepository) { _userRepository = userRepository; } // Parameters from the executing method public void Execute(SomeRole someRole) { someRole.DoStuff(_userRepository); } } The last one seems a bit nicer, but I've never seen it implemented like this so I'm curious if there are any things to consider.

    Read the article

  • Service Layer are repeating my Repositories

    - by Felipe
    Hi all, I'm developing an application using asp.net mvc, NHibernate and DDD. I have a service layer that are used by controllers of my application. Everything are using Unity to inject dependencies (ISessionFactory in repositories, repositories in services and services in controllers) and works fine. But, it's very common I need a method in service to get only object in my repository, like this (in service class): public class ProductService { private readonly IUnitOfWork _uow; private readonly IProductRepository _productRepository; public ProductService(IUnitOfWork unitOfWork, IProductRepository productRepository) { this._uow = unitOfWork; this._productRepository = productRepository; } /* this method should be exists in DDD ??? It's very common */ public Domain.Product Get(long key) { return _productRepository.Get(key); } /* other common method... is correct by DDD ? */ public bool Delete(long key) { usign (var tx = _uow.BeginTransaction()) { try { _productRepository.Delete(key); tx.Commit(); return true; } catch { tx.RollBack(); return false; } } } /* ... others methods ... */ } This code is correct by DDD ? For each Service class I have a Repository, and for each service class need I do a method "Get" for an entity ? Thanks guys Cheers

    Read the article

  • jQuery Hover Fade Button with an Active State

    - by Tim
    I do not want to double post a question; I was trying to post an add-on to my first question that I was looking for additional help. How does one go about this? Here is the original question. jQuery Hover Fade Button with an Active State Was hoping to see if there is a solution to the glitch I found. The problem I am now looking for help with is all other buttons still have the hover effect, but a button that was once active no longer does. <ul class="buttons"> <li><a class="button" href="#">button 1</a></li> <li><a class="button" href="#">button 2</a></li> <li><a class="button" href="#">button 3</a></li> </ul> Best way to explain this. If button 2 is clicked – it is now active. Buttons 1 and 3 will still hover. If you click on button 1 – it is now active and button 2 will no longer hover while button 3 will. Eventually when you go through the series of all buttons the animation hover is no longer.

    Read the article

  • C# ? Can anyone explain the strange behaviour?

    - by partizan
    Hi, guys. Here is the example with comments: class Program { // first version of structure public struct D1 { public double d; public int f; } // during some changes in code then we got D2 from D1 // Field f type became double while it was int before public struct D2 { public double d; public double f; } static void Main(string[] args) { // Scenario with the first version D1 a = new D1(); D1 b = new D1(); a.f = b.f = 1; a.d = 0.0; b.d = -0.0; bool r1 = a.Equals(b); // gives true, all is ok // The same scenario with the new one D2 c = new D2(); D2 d = new D2(); c.f = d.f = 1; c.d = 0.0; d.d = -0.0; bool r2 = c.Equals(d); // false, oops! this is not the result i've expected for } } So, what do you think about this?

    Read the article

  • How am i overriding this C++ inherited member function without the virtual keyword being used?

    - by Gary Willoughby
    I have a small program to demonstrate simple inheritance. I am defining a Dog class which is derived from Mammal. Both classes share a simple member function called ToString(). How is Dog overriding the implementation in the Mammal class, when i'm not using the virtual keyword? (Do i even need to use the virtual keyword to override member functions?) mammal.h #ifndef MAMMAL_H_INCLUDED #define MAMMAL_H_INCLUDED #include <string> class Mammal { public: std::string ToString(); }; #endif // MAMMAL_H_INCLUDED mammal.cpp #include <string> #include "mammal.h" std::string Mammal::ToString() { return "I am a Mammal!"; } dog.h #ifndef DOG_H_INCLUDED #define DOG_H_INCLUDED #include <string> #include "mammal.h" class Dog : public Mammal { public: std::string ToString(); }; #endif // DOG_H_INCLUDED dog.cpp #include <string> #include "dog.h" std::string Dog::ToString() { return "I am a Dog!"; } main.cpp #include <iostream> #include "dog.h" using namespace std; int main() { Dog d; std::cout << d.ToString() << std::endl; return 0; } output I am a Dog! I'm using MingW on Windows via Code::Blocks.

    Read the article

  • jquery fade an element in when a link is clicked and then swap the element when another link is clic

    - by Nik
    I have worked out how to fade an element in: Click here to view the page If you click on the heading Posture 1 : Standing Deep Breathing : you will notice the element fades in as it should. If you now click on posture 2 you will see the element fades in below posture 1. I need to be able to swap posture 1 with posture 2. I have a total of 26 postures that all have images that need to fade in and then be swapped with another image when another heading is clicked. $(document).ready(function(){ $('#section_Q_01,#section_Q_02').hide(); $('h5.trigger#Q_01').click(function(){ $('#section_Q_01').fadeIn(2000) ; }); $('h5.trigger#Q_02').click(function(){ $('#section_Q_02').fadeIn(5000) ; }); }); and the html <div id="section_Q_01" class="01"> <div class="pics"> <img src="../images/multi/poses/pose1/Pranayama._01.jpg"/> <img src="../images/multi/poses/pose1/Pranayama._02.jpg"/> <img src="../images/multi/poses/pose1/Pranayama._03.jpg"/> </div> </div> <div id="section_Q_02" class="02"> <div class="pics"> <img src="../images/multi/poses/pose2/Half_Moon_Pose_04.jpg" /> <img src="../images/multi/poses/pose2/Backward_Bending_05.jpg" /> <img src="../images/multi/poses/pose2/Hands_to_Feet_Pose_06.jpg" /> </div> </div> I need to be able to swap a total of 26 elements #section_Q_01 - #section_Q_26 Any help appreciated

    Read the article

  • Rotate a linked list

    - by user408041
    I want to rotate a linked list that contains a number. 123 should be rotated to 231. The function created 23 but the last character stays empty, why? typedef struct node node; struct node{ char digit; node* p; }; void rotate(node** head){ node* walk= (*head); node* prev= (*head); char temp= walk->digit; while(walk->p!=NULL){ walk->digit=walk->p->digit; walk= walk->p; } walk->digit=temp; } How I create the list: node* convert_to_list(int num){ node * curr, * head; int i=0,length=0; char *arr=NULL; head = NULL; length =(int) log10(((double) num))+1; arr =(char*) malloc((length)*sizeof(char)); //allocate memory sprintf (arr, "%d" ,num); //(num, buf, 10); for(i=length;i>=0;i--) { curr = (node *)malloc(sizeof(node)); (curr)->digit = arr[i]; (curr)->p = head; head = curr; } curr = head; return curr; }

    Read the article

  • Problem in mutiple :dependent=> :destroy when multiple polymorphic is true

    - by piemesons
    I have four models question, answer, comment and vote.Consider it same as stackoverflow. Question has_many comments Answers has_many comments Questions has_many votes answers has_many votes comments has_many votes Here are the models (only relevant things) class Comment < ActiveRecord::Base belongs_to :commentable, :polymorphic => true has_many :votes, :as => :votable, :dependent => :destroy end class Question < ActiveRecord::Base has_many :comments, :as => :commentable, :dependent => :destroy has_many :answers, :dependent => :destroy has_many :votes, :as => :votable, :dependent => :destroy end class Vote < ActiveRecord::Base belongs_to :votable, :polymorphic => true end class Answer < ActiveRecord::Base belongs_to :question, :counter_cache => true has_many :comments, :as => :commentable , :dependent => :destroy end Now the problem is whenever i am trying to delete any question/answer/comment its giving me an error NoMethodError in QuestionsController#destroy undefined method `each' for 0:Fixnum if i remove this line from any of the model (question/answer/comment) has_many :votes, :as => :votable, :dependent => :destroy then it works perfectly. It seems there is a problem while deleting the records active record is not able to find out the proper path because of multiple joins within the tables.

    Read the article

  • Design patterns for Caching Images in a MVC?

    - by Onema
    Hi, I'm designing an image cache system that will be used in an MVC CMS. The main purpose of the image cacher is to modify images: scale, crop, etc and cache them in the client site. I have created an image cache Model and Mapper that interact with the Database, to keep track of the images and know what kind of actions have been applied to them (scale, crop, etc). In addition to the Model and Mapper I have created a ImageCacher Class that is used by the API to manage the Model and image creation based on arguments passed by the client site, this class creates the images and generates the links to the images for the View. A coworker argued that I need to include the functionality of this last Class inside the Model, as the bulk of the logic should go in the model. I respectfully disagree with him since I feel the model's responsibility is to deal with the information about the images cached at the database level, and the responsibility of the ImageCacher Class is to create the url/image that we will be caching (keeping the single responsibility principle). In addition to this I believe that a model should not have Presentation-related features, like creating or showing images. Does anyone have any insight on this? is there a particular design pattern that would make this division of tasks clear and and the image cacher reusable? Should I add all the logic in the Model? Thank you.

    Read the article

  • Foiled by path-dependent types

    - by Ladlestein
    I'm having trouble using, in one trait, a Parser returned from a method in another trait. The compiler complains of a type mismatch and it appears to me that the problem is due to the path-dependent class. I'm not sure how to get what I want. trait Outerparser extends RegexParsers { def inner: Innerparser def quoted[T](something: Parser[T]) = "\"" ~> something <~ "\"" def quotedNumber = quoted(inner.number) // Compile error def quotedLocalNumber = quoted(number) // Compiles just fine def number: Parser[Int] = ("""[1-9][0-9]*"""r) ^^ {str => str.toInt} } trait Innerparser extends RegexParsers { def number: Parser[Int] = ("""[1-9][0-9]*"""r) ^^ {str => str.toInt} } And the error: [error] /Path/to/MyParser.scala:6: type mismatch [error] found : minerals.Innerparser#Parser[Int] [error] required: Outerparser.this.Parser[?] [error] def quotedNumber = quoted(inner.number) I sort-of get the idea: each "something" method is defining a Parser type whose path is specific to the enclosing class (Outerparser or Innerparser). The "quoted" method of Outerparser expects an an instance of type Outerparser.this.Parser but is getting Innerparser#Parser. I like to be able to use quoted with a parser obtained from this class or some other class. How can I do that?

    Read the article

  • I'm confused about Polymorphism

    - by Vtanathip
    I'm know polymorphism rule that we can send it via parameter like this code interface Animal { void whoAmI(); } class A implements Animal{ @Override public void whoAmI() { // TODO Auto-generated method stub System.out.println("A"); } } class B implements Animal{ @Override public void whoAmI() { // TODO Auto-generated method stub System.out.println("B"); } } class RuntimePolymorphismDemo { public void WhoRU(List t){ System.out.println(t.getClass()); } public static void main(String[] args) { A a = new A(); B b = new B(); RuntimePolymorphismDemo rp = new RuntimePolymorphismDemo(); rp.WhoRU(a); rp.WhoRU(b); } } but List<Example> examples = new ArrayList<Example>(); This code,I'm don't understand why we must use List. why we can't use like this? ArrayList<Example> examples = new ArrayList<Example>(); Because when we use List we can't use method that only have in ArrayList class like trimToSize() and How I know when to use or not use?

    Read the article

  • C++ design question, container of instances and pointers

    - by Tom
    Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

    Read the article

  • C++ design question, container of instances and pointers

    - by Tom
    Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

    Read the article

  • C++ design question, container of instances and pointers

    - by Tom
    Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

    Read the article

  • Java Inheritance doubt in parameterised collection

    - by Gala101
    It's obvious that a parent class's object can hold a reference to a child, but does this not hold true in case of parameterised collection ?? eg: Car class is parent of Sedan So public void doSomething(Car c){ ... } public void caller(){ Sedan s = new Sedan(); doSomething(s); } is obviously valid But public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection<Sedan> s = new ArrayList<Sedan>(); doSomething(s); } Fails to compile Can someone please point out why? and also, how to implement such a scenario where a function needs to iterate through a Collection of parent objects, modifying only the fields present in parent class, using parent class methods, but the calling methods (say 3 different methods) pass the collection of three different subtypes.. Ofcourse it compiles fine if I do as below: public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection s = new ArrayList<Sedan>(); doSomething(s); }

    Read the article

  • Nested bind expressions

    - by user328543
    This is a followup question to my previous question. #include <functional> int foo(void) {return 2;} class bar { public: int operator() (void) {return 3;}; int something(int a) {return a;}; }; template <class C> auto func(C&& c) -> decltype(c()) { return c(); } template <class C> int doit(C&& c) { return c();} template <class C> void func_wrapper(C&& c) { func( std::bind(doit<C>, std::forward<C>(c)) ); } int main(int argc, char* argv[]) { // call with a function pointer func(foo); func_wrapper(foo); // error // call with a member function bar b; func(b); func_wrapper(b); // call with a bind expression func(std::bind(&bar::something, b, 42)); func_wrapper(std::bind(&bar::something, b, 42)); // error // call with a lambda expression func( [](void)->int {return 42;} ); func_wrapper( [](void)->int {return 42;} ); return 0; } I'm getting a compile errors deep in the C++ headers: functional:1137: error: invalid initialization of reference of type ‘int (&)()’ from expression of type ‘int (*)()’ functional:1137: error: conversion from ‘int’ to non-scalar type ‘std::_Bind(bar, int)’ requested func_wrapper(foo) is supposed to execute func(doit(foo)). In the real code it packages the function for a thread to execute. func would the function executed by the other thread, doit sits in between to check for unhandled exceptions and to clean up. But the additional bind in func_wrapper messes things up...

    Read the article

  • Are vector assignments copied by value or by reference in Google's Go language?

    - by Brian T Hannan
    In the following code, I create one peg puzzle then do a move on it which adds a move to its movesAlreadyDone vector. Then I create another peg puzzle then do a move on it which adds a move to its movesAlreadyDone vector. When I print out the values in that vector for the second one, it has the move in it from the first one along with the move from the second one. Can anyone tell me why it seems to be assigning by reference and not value? Are vector assignments copied by value or by reference in Google's Go language? package main import "fmt" import "container/vector" type Move struct { x0, y0, x1, y1 int } type PegPuzzle struct { movesAlreadyDone * vector.Vector; } func (p *PegPuzzle) InitPegPuzzle(){ p.movesAlreadyDone = vector.New(0); } func NewChildPegPuzzle(parent *PegPuzzle) *PegPuzzle{ retVal := new(PegPuzzle); retVal.movesAlreadyDone = parent.movesAlreadyDone; return retVal } func (p *PegPuzzle) doMove(move Move){ p.movesAlreadyDone.Push(move); } func (p *PegPuzzle) printPuzzleInfo(){ fmt.Printf("-----------START----------------------\n"); fmt.Printf("moves already done: %v\n", p.movesAlreadyDone); fmt.Printf("------------END-----------------------\n"); } func main() { p := new(PegPuzzle); cp1 := new(PegPuzzle); cp2 := new(PegPuzzle); p.InitPegPuzzle(); cp1 = NewChildPegPuzzle(p); cp1.doMove(Move{1,1,2,3}); cp1.printPuzzleInfo(); cp2 = NewChildPegPuzzle(p); cp2.doMove(Move{3,2,5,1}); cp2.printPuzzleInfo(); } Any help will be greatly appreciated. Thanks!

    Read the article

  • Design issue when having classes implement different interfaces to restrict client actions

    - by devoured elysium
    Let's say I'm defining a game class that implements two different views: interface IPlayerView { void play(); } interface IDealerView { void deal(); } The view that a game sees when playing the game, and a view that the dealer sees when dealing the game (this is, a player can't make dealer actions and a dealer can't make player actions). The game definition is as following: class Game : IPlayerView, IDealerView { void play() { ... } void deal() { ... } } Now assume I want to make it possible for the players to play the game, but not to deal it. My original idea was that instead of having public Game GetGame() { ... } I'd have something like public IPlayerView GetGame() { ... } But after some tests I realized that if I later try this code, it works: IDealerView dealerView = (IDealerView)GameClass.GetGame(); this works as lets the user act as the dealer. Am I worrying to much? How do you usually deal with this patterns? I could instead make two different classes, maybe a "main" class, the dealer class, that would act as factory of player classes. That way I could control exactly what I would like to pass on the the public. On the other hand, that turns everything a bit more complex than with this original design. Thanks

    Read the article

< Previous Page | 718 719 720 721 722 723 724 725 726 727 728 729  | Next Page >