Search Results

Search found 8330 results on 334 pages for 'template inheritance'.

Page 82/334 | < Previous Page | 78 79 80 81 82 83 84 85 86 87 88 89  | Next Page >

  • class T in c++ (your definition)

    - by JohnWong
    The one advantage of using class T in c++ is to reduce the time to redefine data types in a function, if those data types are defined in other function, for example, in int main. template <class T> void showabs(T number) { if (number < 0 ) number = -number; cout << number << endl; return 0; } int main() { int num1 = -4; float num2 = -4.23f; showabs(num1); showabs(num2); return 0; } So in this case, without class T, for each data type, we have to add its corresponding data-type condition, that is, another set of if statement for int, and another one for float. Am I correct?

    Read the article

  • How do I inherit abstract unit tests in Ruby?

    - by Graeme Moss
    I have two unit tests that should share a lot of common tests with slightly different setup methods. If I write something like class Abstract < Test::Unit::TestCase def setup @field = create end def test_1 ... end end class Concrete1 < Abstract def create SomeClass1.new end end class Concrete2 < Abstract def create SomeClass2.new end end then Concrete1 does not seem to inherit the tests from Abstract. Or at least I cannot get them to run in eclipse. If I choose "Run all TestCases" for the file that contains Concrete1 then Abstract is run even though I do not want it to be. If I specify Concrete1 then it does not run any tests at all! If I specify test_1 in Concrete1 then it complains it cannot find it ("uncaught throw :invalid_test (ArgumentError)"). I'm new to Ruby. What am I missing here?

    Read the article

  • Java : Using parent class method to access child class variable

    - by Jayant
    I have the following scenario : public class A { private int x = 5; public void print() { System.out.println(x); } } public class B extends A { private int x = 10; /*public void print() { System.out.println(x); }*/ public static void main(String[] args) { B b = new B(); b.print(); } } On executing the code, the output is : 5. How to access the child class(B's) variable(x) via the parent class method? Could this be done without overriding the print() method (i.e. uncommenting it in B)? [This is important because on overriding we will have to rewrite the whole code for the print() method again]

    Read the article

  • Is there any difference these two pieces of code?

    - by Poiuyt
    #include<stdio.h> class A {public: int a; }; class B: public A {private: int a;}; int main(){ B b; printf("%d", b.a); return 0; } #include<stdio.h> class A {public: int a; }; class B: private A {}; int main(){ B b; printf("%d", b.a); return 0; } I ask because I get different errors: error: 'int B::a' is private error: 'int A::a' is inaccessible Apart from what the errors might reveal, is there any difference at all in the behaviour of these two pieces of code?

    Read the article

  • base pointer to derived class

    - by Jay
    Suppose there are Base class and Derived class. Base *A = new Base; Here A is a pointer point to Base class, and new constructs one that A points to. I also saw Base *B = new Derived; How to explain this? B is a pointer to Base Class, and a Derived class constructed and pointed by B? If there is a function derived from Base class, say, Virtual void f(), and it's been overridden in Derived class, then B->f() will invoke which version of the function? version in Base class, or version that overridden in Derived Class. What if there is a new function void g()in Derived, is B->g() going to invoke this function properly? One more is, is int *a = new double; or int *a = new int; legal?

    Read the article

  • Javascript: Inherit method from base class and return the subclass's private variable

    - by marisbest2
    I have the following BaseClass defined: function BaseClass (arg1,arg2,arg3) { //constructor code here then - var privateVar = 7500; this.getPrivateVar = function() { return privateVar; }; } I want to have the following subclass which allows changing privateVar like so: function SubClass (arg1,arg2,arg3,privateVar) { //constructor code here then - var privateVar = privateVar; } SubClass.prototype = new BaseClass(); Now I want SubClass to inherit the getPrivateVar method. However, when I try this, it always returns 7500 which is the value in the BaseClass and not the value of privateVar. In other words, is it possible to inherit a BaseClass's public methods but have any references in them refer to the SubClass's properties? And how would I do that?

    Read the article

  • Force the use of interface instead of concrete implementation in declaration (.NET)

    - by gammelgul
    In C++, you can do the following: class base_class { public: virtual void do_something() = 0; }; class derived_class : public base_class { private: virtual void do_something() { std::cout << "do_something() called"; } }; The derived_class overrides the method do_something() and makes it private. The effect is, that the only way to call this method is like this: base_class *object = new derived_class(); object->do_something(); If you declare the object as of type derived_class, you can't call the method because it's private: derived_class *object = new derived_class(); object->do_something(); // --> error C2248: '::derived_class::do_something' : cannot access private member declared in class '::derived_class' I think this is quite nice, because if you create an abstract class that is used as an interface, you can make sure that nobody accidentally declares a field as the concrete type, but always uses the interface class. Since in C# / .NET in general, you aren't allowed to narrow the access from public to private when overriding a method, is there a way to achieve a similar effect here?

    Read the article

  • Similar Sub-Classes

    - by praks5432
    Lets say I have a class A that is fairly simple like this - public class A{ private int randomField = 0; protected int key; protected double dmg; } Now I want to write a number of sub-classes that inherit the protected fields and only differ based on the initial values that are assigned to those fields - for example, if I wrote two subclasses B and C, the only difference between those two sub-classes would be that the values key and dmg would have different values. They would share a method, set, which would be exactly the same, in that it would affect the same variable. I find when I'm writing these sub-classes I'm repeating myself, as I just change the constructor to set different initial values to key and dmg, and simply copy and paste the set method. Is there a 'good' way to do this?

    Read the article

  • Friendly way to override `const`-overloaded member function?

    - by xtofl
    Given a base class class A { int i; public: int& f(){ return i;} const int& f() const { return i;} }; And a sub class class ConstA : private A { public: const int& f() const { return A::f(); } }; Is there a wrist-friendly way to access the ConstA::f method on a non-const variable? ConstA ca; int i = ca.f(); // compile error: int& A::f() is not accessible since A is privately inherited int j = static_cast<const ConstA&>(ca).f(); // this works, but it hurts a little... Or is it so ugly since hiding A::f generally is a bad idea, violating the Liskov Substitution Principle: any subclass of A must at least be capable of all A's functionality? void set( A& a, int i ) { a.f() = i; } class ConstA2 : public A { private: int& f(){ return A::f(); } }; ConstA2 ca2; set( ca2, 1 ); (Note: this question popped up while thinking about this question)

    Read the article

  • How to access base (super) class in Delphi?

    - by Niyoko Yuliawan
    In C# i can access base class by base keyword, and in java i can access it by super keyword. How to do that in delphi? suppose I have following code: type TForm3 = class(TForm) private procedure _setCaption(Value:String); public property Caption:string write _setCaption; //adding override here gives error end; implementation procedure TForm3._setCaption(Value: String); begin Self.Caption := Value; //it gives stack overflow end;

    Read the article

  • Remove .img css from prepended div

    - by Ivan Schrecklich
    OK as the title says I've got a div which is prepended and dynamically loaded. The problem I have is that I can't split the css on this one as it parses also whole strings. The usage is like that: I've got a @username somewhere in the string. If the user hovers it a div with informations will get prepended to the current username. Now there is the problem that I've allowed users to post images in this text also. As the autolinker is flexible it doesn't know the image sizes and restrictions and I want to leave it like that! So I define css classes which look like that: .minpost img{ max-height: 30px; max-width: 30px; } Of course I don't need to mention that this attribute is also inherited by the prepended div. And that I don't want to! nifty little tricks like !important won't work for me. So I am asking you guys. If you need further informations just ask?!

    Read the article

  • Use of .apply() with 'new' operator. Is this possible?

    - by Premasagar
    In JavaScript, I want to create an object instance (via the new operator), but pass an arbitrary number of arguments to the constructor. Is this possible? What I want to do is something like this (but the code below does not work): function Something(){ // init stuff } function createSomething(){ return new Something.apply(null, arguments); } var s = createSomething(a,b,c); // 's' is an instance of Something The Answer From the responses here, it became clear that there's no in-built way to call .apply() with the new operator. However, people suggested a number of really interesting solutions to the problem. My preferred solution was this one from Matthew Crumley (I've modified it to pass the arguments property): var createSomething = (function() { function F(args) { return Something.apply(this, args); } F.prototype = Something.prototype; return function() { return new F(arguments); } })();

    Read the article

  • setting up 301 redirects: dynamic urls to static urls

    - by MS
    We are currently using a template-based website and are hoping to move to a site with static urls. Our domain will stay the same. I understand that using 301 redirects in a .htaccess file is the preferred method -- and the one that has the highest chance of preserving our google rankings. I am still new at all this and am having a hard time figuring out the proper way to code it all. Over a hundred of our pages are indexed. They all have a similar URL but with different pageIDs: http://www.realestate-bigbear.com/Nav.aspx/Page=%2fPageManager%2fDefault.aspx%2fPageID%3d2020765 Some link out to provided content, ex. /RealEstateNews/Default.aspx Then there are many that flow from the main featured listings page: /ListNow/Default.aspx Down to all the specific properties.. where the PropertyId changes /ListNow/Property.aspx?PropertyID=2048098 would a simple set of codes work... like the following.... redirect 301 /Nav.aspx/Page=%2fPageManager%2fDefault.aspx%2fPageID%3d2020765 www.realestate.bigbear.com/SearchBigBearMLS.htm or do I need to do something entirely different?

    Read the article

  • how to change mod_mainmenu output structure in joomla

    - by Prakash
    how is it possible to change the mod_mainmenu output structure as below by using mod_mainmenu template. Note here class="box1", class="box2", class="box3", class="box4" will fetched dynamically. <ul class="menu"> <li class=""> <a href="#" class="box1"><span>Menu 1</span></a> </li> <li class="current"> <a href="#" class="box2"><span>Menu 2</span></a> <ul class="box2"> <li><a href="#">Sub Menu 1</a></li> <li><a href="#">Sub Menu 2</a></li> <li><a href="#">Sub Menu 3</a></li> </ul> </li> <li class=""> <a href="#" class="box3"><span>Menu 3</span></a> </li> <li class=""> <a href="#" class="box4"><span>Menu 4</span></a> </li> </ul>

    Read the article

  • derived class as default argument g++

    - by Vincent
    Please take a look at this code: template<class T> class A { class base { }; class derived : public A<T>::base { }; public: int f(typename A<T>::base& arg = typename A<T>::derived()) { return 0; } }; int main() { A<int> a; a.f(); return 0; } Compiling generates the following error message in g++: test.cpp: In function 'int main()': test.cpp:25: error: default argument for parameter of type 'A<int>::base&' has type 'A<int>::derived' The basic idea (using derived class as default value for base-reference-type argument) works in visual studio, but not in g++. I have to publish my code to the university server where they compile it with gcc. What can I do? Is there something I am missing?

    Read the article

  • [C++] My First Go With Function Templates

    - by bobber205
    Thought it was pretty straight forward. But I get a "iterator not dereferencable" errro when running the below code. What's wrong? template<typename T> struct SumsTo : public std::binary_function<T, T, bool> { int myInt; SumsTo(int a) { myInt = a; } bool operator()(const T& l, const T& r) { cout << l << " + " << r; if ((l + r) == myInt) { cout << " does add to " << myInt; } else { cout << " DOES NOT add to " << myInt; } return true; } }; void main() { list<int> l1; l1.push_back(1); l1.push_back(2); l1.push_back(3); l1.push_back(4); list<int> l2; l2.push_back(9); l2.push_back(8); l2.push_back(7); l2.push_back(6); transform(l1.begin(), l1.end(), l2.begin(), l2.end(), SumsTo<int>(10) ); }

    Read the article

  • PHP: Opening/closing tags & performance?

    - by Tom
    Hi, This may be a silly question, but as someone relatively new to PHP, I'm wondering if there are any performance-related issues to frequently opening and closing PHP tags in HTML template code, and if so, what might be best practices in terms of working with php tags? My question is not about the importance/correctness of closing tags, or about which type of code is more readable than another, but rather about how the document gets parsed/executed and what impact it might have on performance. To illustrate, consider the following two extremes: Mixing PHP and HTML tags: <?php echo '<tr> <td>'.$variable1.'</td> <td>'.$variable2.'</td> <td>'.$variable3.'</td> <td>'.$variable4.'</td> <td>'.$variable5.'</td> </tr>' ?> // PHP tag opened once Separating PHP and HTML tags: <tr> <td><?php echo $variable1 ?></td> <td><?php echo $variable2 ?></td> <td><?php echo $variable3 ?></td> <td><?php echo $variable4 ?></td> <td><?php echo $variable5 ?></td> </tr> // PHP tag opened five times Would be interested in hearing some views on this, even if it's just to hear that it makes no difference. Thanks.

    Read the article

  • CodeIgniter - the right way to create "block" elements on web page

    - by kikkoman90
    Hello. I've been searching for a solutions for this problem a while but haven't seen any "valid mvc" solution for this. I hope I can explain my problem clearly enough for you guys. I need to create a dynamic block of HTML on my website. (eg. a block containing user's latest blog comments). I have a template view file (a file containing header, content container and a footer) where I need to add some content AND this block element. The problem is that I don't want to duplicate this block code on every controller. It just feels stupid and I'm sure there's a better way to do this than just duplicating same stuff all over again on all the controller files? I can add view inside another view just fine, but what bugs me is how to actually generate that dynamic content to this block's view-file. I can't call controller from view file, controller from controller filem or model from view file because what I understand that just isn't the "mvc" way? Anyone got any tricks or tips for this?

    Read the article

  • HTML templating in C++ and translations

    - by Karim
    I'm using HTML_Template for templating in my C++-based web app (don't ask). I chose that because it was very simple and it turns out to be a good solution. The only problem right now is that I would like to be able to include translatable strings in the HTML templates (HTML_Template does not really support that). Ultimately, what I would like is to have a single file that contains all the strings to be translated. It can then be given to a translator and plugged back in to the app and used depending on which language the user chose in settings. I've been going back and forth on some options and was wondering what others felt was the best choice (or if there's a better choice that isn't listed) Extend HTML_Template to include a tag for holding the literal string to translate. So, for example, in the HTML I would put something like <TMPL_TRANS "this is the text to translate"/> Use a completely separate scheme for translation and preprocess the HTML files to generate the final template files (without the special translation lingo). For example, in the pre-processed file, translatable text would look like this: {{this is the text to translate}} and the final would look like: this is the text to translate Don't do anything and let the translators find the string to translate in the html and js files themselves.

    Read the article

  • Null pointer to struct which has zero size (empty)... It is a good practice?

    - by ProgramWriter
    Hi2All.. I have some null struct, for example: struct null_type { NullType& someNonVirtualMethod() { return *this; } }; And in some function i need to pass reference to this type. Reason: template <typename T1 = null_type, typename T2 = null_type, ... > class LooksLikeATupleButItsNotATuple { public: LooksLikeATupleButItsNotATuple(T1& ref1 = defParamHere, T2& ref2 = andHere..) : _ref1(ref1), _ref2(ref2), ... { } void someCompositeFunctionHere() { _ref1.someNonVirtualMethod(); _ref2.someNonVirtualMethod(); ... } private: T1& _ref1; T2& _ref2; ...; }; It is a good practice to use null reference as a default parameter?: *static_cast<NullType*>(0) It works on MSVC, but i have some doubts...

    Read the article

  • Is context inheritance, as shown by Head First Design Patterns' Duck example, irrelevant to strategy pattern?

    - by Korey Hinton
    In Head First Design Patterns it teaches the strategy pattern by using a Duck example where different subclasses of Duck can be assigned a particular behavior at runtime. From my understanding the purpose of the strategy pattern is to change an object's behavior at runtime. Emphasis on "an" meaning one. Could I further simplify this example by just having a Duck class (no derived classes)? Then when implementing one duck object it can be assigned different behaviors based on certain circumstances that aren't dependent on its own object type. For example: FlyBehavior changes based on the weather or QuackBehavior changes based on the time of day or how hungry a duck is. Would my example above constitute the strategy pattern as well? Is context inheritance (Duck) irrelevant to the strategy pattern or is that the reason for the strategy pattern? Here is the UML diagram from the Head First book:

    Read the article

  • WPF Custom Control - Designer looks fine, but I get a runtime issue...

    - by myermian
    MainWindow.xaml <Window x:Class="MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:my="clr-namespace:MyStuff;assembly=MyStuff" Title="MainWindow" Height="350" Width="525"> <Grid> <TabControl Margin="5"> <TabItem Header="Start Page" /> <my:XTabItem Header="Tab 1" Image="Resources/icon1.png" /> </TabControl> </Grid> </Window> Generic.xaml <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:MyStuff" > <!-- XTabItem --> <Style TargetType="{x:Type local:XTabItem}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type local:XTabItem}"> <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}"> <StackPanel Orientation="Horizontal"> <Image Source="{Binding Path=Image, RelativeSource={RelativeSource TemplatedParent}}" Stretch="UniformToFill" MaxHeight="24" /> <TextBlock Text="{TemplateBinding Header}" /> <Button Content="X" /> </StackPanel> </Border> </ControlTemplate> </Setter.Value> </Setter> </Style> </ResourceDictionary> XTabItem.cs using System; using System.ComponentModel; using System.Windows; using System.Windows.Controls; using System.Windows.Media; namespace MyStuff { public class XTabItem : TabItem { #region Dependency Properties public static readonly DependencyProperty ImageProperty; #endregion #region Constructors / Initializer static XTabItem() { //Initialize the control as "lookless". DefaultStyleKeyProperty.OverrideMetadata(typeof(XTabItem), new FrameworkPropertyMetadata(typeof(XTabItem))); //Setup the dependency properties. ImageProperty = DependencyProperty.Register("Image", typeof(ImageSource), typeof(XTabItem), new UIPropertyMetadata(null)); } #endregion #region Custom Control Properties (Image) /// <summary> /// The image (icon) displayed by inside the tab header. /// </summary> /// <remarks>The image is specified in XAML as an absolute or relative path.</remarks> [Description("The image displayed by the button"), Category("Optional Properties")] public ImageSource Image { get { return (ImageSource)GetValue(ImageProperty); } set { SetValue(ImageProperty, value); } } #endregion } } Exception at line #9 () : XamlParseException : 'Provide value on 'System.Windows.Baml2006.TypeConverterMarkupExtension' threw an exception.' Line number '9' and line position '27'.

    Read the article

< Previous Page | 78 79 80 81 82 83 84 85 86 87 88 89  | Next Page >