Search Results

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

Page 155/334 | < Previous Page | 151 152 153 154 155 156 157 158 159 160 161 162  | Next Page >

  • What is the sense of "Feature Oriented Programming" (FOP) in C++, and would it make sense in Java an

    - by ivan_ivanovich_ivanoff
    Hello! Sadly, I can't remember where I read it, but... ...in C++ you can derive a class from a template parameter. Im pretty sure it was called Feature Oriented Programming (FOP) and meant to be somehow useful. It was something like: template <class T> class my_class : T { // some very useful stuff goes here ;) } My questions about this: What is the sense of such pattern? Since this it not possible in Java / C#, how this pattern is achieved in these languages? Can it be expected to be implemented in Java / C# one day? (Well, first Java would need to get rid of type erasure) EDIT: I'm really not talking about generics in Java / C# (where you can't derive a class from a generic type parameter)

    Read the article

  • Active Scaffold + Ruby 2.3.5 not working

    - by rodrigoaronas
    Hello, I have an application with Rails 2.3.5. And Im trying to use AS latest version, I have used it previously but cant make it work here. I have my ingredient_categories Controller, where i put class Administration::IngredientCategoriesController < ApplicationController layout "default" active_scaffold :ingredient_categories end I have this set up on routes to be :active_scaffold=true I have a model also called ingredient_category, and in the views folder (inside administration/ingredient_categories, and /ingredient_categories) i have nothing as it is usual. And Im getting over and over again: Template is missing Missing template ingredient_categories/list.html in view path themes/aqueouslight:app/views I had an error before asking me for a list.erb, which I created and put <%= render :active_scaffold = 'ingredient_categories', :label = 'Categorias' % And now this error of the list.thml... Cant make it work! dont know whhy really... whould be SO simple and its burning my head now.. Thanks!

    Read the article

  • Is correct name enough to make it happen?

    - by Knowing me knowing you
    Guys, I've just dipped in to limits.h by MS. I tried to check what's the return type for max() fnc and to my surprise I see something like this: // TEMPLATE CLASS numeric_limits template<class _Ty> class numeric_limits : public _Num_base { // numeric limits for arbitrary type _Ty (say little or nothing) public: static _Ty (__CRTDECL min)() _THROW0() { // return minimum value return (_Ty(0)); } static _Ty (__CRTDECL max)() _THROW0() { // return maximum value return (_Ty(0));//EXACTLY THE SAME WHAT IN min<<------------------ } //... other stuff }; so how is it possiple that in both min and max return does exactly the same? So does it mean if I would write makeSanwich() return (_Ty(0)) it would make a sandwich for me? How is it possible that having this same code just fnc names different we are getting different results?

    Read the article

  • Detect if a method was overridden using Reflection (C#)

    - by Andrey
    Say I have a base class TestBase where I define a vistual method TestMe() class TestBase { public virtual bool TestMe() { } } Now I inherit this class: class Test1 : TestBase { public override bool TestMe() {} } Now, using Reflection, I need to find if the method TestMe has been overriden in child class - is it possible? What I need it for - I am writing a designer visualizer for type "object" to show the whole hierarchy of inheritance and also show which virtual methods were overridden at which level.

    Read the article

  • Compare images to find differences

    - by _simon_
    Task: I have a camera mounted on the end of our assembly line, which captures images of produced items. Let's for example say, that we produce tickets (with some text and pictures on them). So every produced ticket is photographed and saved to disk as image. Now I would like to check these saved images for anomalies (i.e. compare them to an image (a template), which is OK). So if there is a problem with a ticket on our assembly line (missing picture, a stain,...), my application should find it (because its image differs too much from my template). Question: What is the easiest way to compare pictures and find differences between them? Do I need to write my own methods, or can I use existing ones? It would be great if I just set a tolerance value (i.e. images can differ for 1%), put both images in a function and get a return value of true or false :) Tools: C# or VB.NET, Emgu.CV (.NET wrapper for OpenCV) or something similar

    Read the article

  • Features to remove from C++

    - by Justin Ethier
    This question was inspired by What features would you like to see added to C++? (also see What features do you miss in C++?). C++ is a great general-purpose language, but perhaps too general and feature-rich: multiple inheritance, operator overloading, manual memory management, templates, smart pointers, virtual destructors, legacy frameworks (think MFC), and I could go on. Is there any one feature or aspect of C++ that you would like removed to make our lives easier as C++ developers? One feature per answer, please.

    Read the article

  • C++0x class factory with variadic templates problem

    - by randomenglishbloke
    I have a class factory where I'm using variadic templates for the c'tor parameters (code below). However, when I attempt to use it, I get compile errors; when I originally wrote it without parameters, it worked fine. Here is the class: template< class Base, typename KeyType, class... Args > class GenericFactory { public: GenericFactory(const GenericFactory&) = delete; GenericFactory &operator=(const GenericFactory&) = delete; typedef Base* (*FactFunType)(Args...); template <class Derived> static void Register(const KeyType &key, FactFunType fn) { FnList[key] = fn; } static Base* Create(const KeyType &key, Args... args) { auto iter = FnList.find(key); if (iter == FnList.end()) return 0; else return (iter->second)(args...); } static GenericFactory &Instance() { static GenericFactory gf; return gf; } private: GenericFactory() = default; typedef std::unordered_map<KeyType, FactFunType> FnMap; static FnMap FnList; }; template <class B, class D, typename KeyType, class... Args> class RegisterClass { public: RegisterClass(const KeyType &key) { GenericFactory<B, KeyType, Args...>::Instance().Register(key, FactFn); } static B *FactFn(Args... args) { return new D(args...); } }; Here is the error: when calling (e.g.) // Tucked out of the way RegisterClass<DataMap, PDColumnMap, int, void *> RC_CT_PD(0); GCC 4.5.0 gives me: In constructor 'RegisterClass<B, D, KeyType, Args>::RegisterClass(const KeyType&) [with B = DataMap, D = PDColumnMap, KeyType = int, Args = {void*}]': no matching function for call to 'GenericFactory<DataMap, int, void*>::Register(const int&, DataMap* (&)(void*))' I can't see why it won't compile and after extensive googling I couldn't find the answer. Can anyone tell me what I'm doing wrong (aside from the strange variable name, which makes sense in context)?

    Read the article

  • Does a child control inherit its parents properties of the same name

    - by Dave Colwell
    Hi all, simple question regarding property value inheritance in UserControls. If i create a UserControl, it has some standard properties like Background, BorderBrush and BorderThickness. Within that UserControl i have a border. I want to know, if i dont specify any set value or binding for the property BorderBrush of that border, will it automatically inherit the value of BorderBrush from the parent control? Thanks!

    Read the article

  • Another thread safe queue implementation

    - by jensph
    I have a class, Queue, that I tried to make thread safe. It has these three member variables: std::queue<T> m_queue; pthread_mutex_t m_mutex; pthread_cond_t m_condition; and a push and pop implemented as: template<class T> void Queue<T>::push(T value) { pthread_mutex_lock( &m_mutex ); m_queue.push(value); if( !m_queue.empty() ) { pthread_cond_signal( &m_condition ); } pthread_mutex_unlock( &m_mutex ); } template<class T> bool Queue<T>::pop(T& value, bool block) { bool rtn = false; pthread_mutex_lock( &m_mutex ); if( block ) { while( m_queue.empty() ) { pthread_cond_wait( &m_condition, &m_mutex ); } } if( !m_queue.empty() ) { value = m_queue.front(); m_queue.pop(); rtn = true; } pthread_mutex_unlock( &m_mutex ); return rtn; } Unfortunately there are occasional issues that may be the fault of this code. That is, there are two threads and sometimes thread 1 never comes out of push() and at other times thread 2 never comes out of pop() (the block parameter is true) though the queue isn't empty. I understand there are other implementations available, but I'd like to try to fix this code, if needed. Anyone see any issues? The constructor has the appropriate initializations: Queue() { pthread_mutex_init( &mMutex, NULL ); pthread_cond_init( &mCondition, NULL ); } and the destructor, the corresponding 'destroy' calls.

    Read the article

  • Magento - Using alternative "reviews count" on category list page

    - by Sam
    Hi All I noticed that on the category list page, the number of reviews (pulled from frontend/base/default/template/review/helper/summary_short.phtml) lists the full amount of reviews for an item, not the amount available to the store view you’re on. So, for example (using the sample data) the Samsung MM-A900M Ace has 5 reviews - however, when you click that link and are taken to the reviews page, it actually just has 2 (as only 2 are available to the English view). But on the reviews page, the review count is correct and says 2 reviews (this time pulled from frontend/base/default/template/review/product/view/count.phtml). Is there any way to use this review count on the category list?

    Read the article

  • What are the standard practices for throwing Javascript Exceptions?

    - by T.R.
    w3schools says that exceptions can be strings, integers, booleans, or objects, but the example given doesn't strike me as good practice, since exception type checking is done through string comparison. Is this the preferred method of exception handling in Javascript? Are there built-in exception types (like NullPointerException)? (if so, what are they, what kind of inheritance do they use, and are they preferred over other options?)

    Read the article

  • XSLT Exclude Specific Tags

    - by MMKD
    I have a problem i am trying to resolve in an XSLT but i an unable to find a solution. The example below is related to a payment system it is adding items to a basket then removing them. The out XML provides a audit trail of actions conducted on a basket. Senario: Add Item (Id 1) Add Item (Id 1) With a price change Void Item (Id 1) Void Item (Id 1) With a price change Add Item (Id 1) Add Item (Id 1) Expected Outcome Remove: Add Item (Id 1) Add Item (Id 1) With a price change Output XML Contains Void Item (Id 1) Void Item (Id 1) With a price change Add Item (Id 1) Add Item (Id 1) Input XML: <xml> <product void="false"> <sequence_number>1</sequence_number> <item_id>11111111</item_id> <price>12</price> </product> <product void="false"> <sequence_number>2</sequence_number> <item_id>11111111</item_id> <price>12</price> <price_change> <price>10</price> </price_change> </product> <product void="true"> <sequence_number>3</sequence_number> <item_id>11111111</item_id> <price>12</price> <price_change> <price>10</price> </price_change> </product> <product void="true"> <sequence_number>4</sequence_number> <item_id>11111111</item_id> <price>12</price> </product> <product void="false"> <sequence_number>5</sequence_number> <item_id>11111111</item_id> <price>12</price> </product> <product void="false"> <sequence_number>6</sequence_number> <item_id>11111111</item_id> <price>12</price> </product> </xml> Expected outcome: <xml> <product void="true"> <sequence_number>3</sequence_number> <item_id>11111111</item_id> <price>12</price> <price_change> <price>10</price> </price_change> </product> <product void="true"> <sequence_number>4</sequence_number> <item_id>11111111</item_id> <price>12</price> </product> <product void="false"> <sequence_number>5</sequence_number> <item_id>11111111</item_id> <price>12</price> </product> <product void="false"> <sequence_number>6</sequence_number> <item_id>11111111</item_id> <price>12</price> </product> </xml> XSLT <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="@*|node()"> <xsl:copy> <xsl:apply-templates select="@*|node()"/> </xsl:copy> </xsl:template> <xsl:template match="//product[@void='false']"> <xsl:if test="item_id != //product[@void='true']/item_id"> <xsl:copy> <xsl:apply-templates select="@*|node()"/> </xsl:copy> </xsl:if> </xsl:template> </xsl:stylesheet> The problem with this is that it is deleting all products that are not voided and have the same id and not taking into account the number of void items vs the number of none void items. If you have 1 void item it should only delete one product that is not voided but has exactly the same tags as itself

    Read the article

  • Why can't your switch statement data type be long Java?

    - by Fostah
    Here's an excerpt from Sun's Java tutorials: A switch works with the byte, short, char, and int primitive data types. It also works with enumerated types (discussed in Classes and Inheritance) and a few special classes that "wrap" certain primitive types: Character, Byte, Short, and Integer (discussed in Simple Data Objects ). There must be a good reason why the long primitive data type is not allowed. Anyone know what it is?

    Read the article

  • Why do you sometimes need to write <typename T> instead of just <T> ?

    - by StackedCrooked
    I was reading the Wikipedia article on SFINAE and encountered following code sample: struct Test { typedef int Type; }; template < typename T > void f( typename T::Type ) {} // definition #1 template < typename T > void f( T ) {} // definition #2 void foo() { f< Test > ( 10 ); //call #1 f< int > ( 10 ); //call #2 without error thanks to SFINAE } Now I've actually written code like this before, and somehow intuitively I knew that I needed to type "typename T" instead of just "T". However, it would be nice to know the actual logic behind it. Anyone care to explain?

    Read the article

  • Magento - createBlock() in controller, can I access this in layout.xml?

    - by pspahn
    I have an index controller with a view action that does the following: echo $this->getLayout() ->createBlock('core/template','builder') ->setTemplate('pages/builder/view.phtml') ->setHeaderText($extra->getHeaderText()) ->setFooterText($extra->getFooterText()) ->setProducts($collection) ->toHtml(); Based on this, I am trying to perform layout updates in builder.xml (which is being set in the module's config.xml). However, I am not sure if you can target blocks instantiated in this manner. Based on the above block creation, am I able to perform the following: <layout version="0.1.0"> <builder_index_view> <!-- shouldn't this reference the createBlock() name argument? --> <reference name="builder"> <block type="page/html_header" name="builder.header" as="builder.header" template="pages/builder/header.phtml"/> </reference> </builder_index_view> </layout>

    Read the article

  • c++ manipulator question

    - by robert
    i have a class: template<class T> class matrix { private: int COLS,ROWS; public: inline matrix(int r,int c){ this->COLS=r; this->ROWS=c; } template<class T2> friend ostream& info(ostream& os); }; i tried in so many ways to implement the info class.but none is succeed. i want to use it in main function Matrix<int> M(10,20); cout<<info<<M; i want to out put the Matrix class's cols, and rows information. i have tried so many time in implementing the friend class info, but failed. any one can tell me how can do it?

    Read the article

  • How to select random image of specific size using Django / Python?

    - by Jonathan
    I've been using this little snippet to select random images. However I would like to change it to select only images of a certain size. I'm running into trouble checking against image size. If I use get_image_dimensions() I need to use a conditional statement, which then requires that I allow exceptions. So, I guess I need some pointers on just limiting by image dimensions. Thanks. import os import random import posixpath from django import template from django.conf import settings register = template.Library() def is_image_file(filename): """Does `filename` appear to be an image file?""" img_types = [".jpg", ".jpeg", ".png", ".gif"] ext = os.path.splitext(filename)[1] return ext in img_types @register.simple_tag def random_image(path): """ Select a random image file from the provided directory and return its href. `path` should be relative to MEDIA_ROOT. Usage: <img src='{% random_image "images/whatever/" %}'> """ fullpath = os.path.join(settings.MEDIA_ROOT, path) filenames = [f for f in os.listdir(fullpath) if is_image_file(f)] pick = random.choice(filenames) return posixpath.join(settings.MEDIA_URL, path, pick)

    Read the article

  • Rendering HTML in rails without actually displaying it

    - by Kevin Whitaker
    Hello all, My current project requires me to assemble a .zip file containing HTML and text-only templates for a user to download, for importing into an email marketing program. I've inherited this project, and currently the code uses a "fake" model (that is a model that does not directly correlate to a database table), in which it stores the entire template in a string, using dynamic variables to populate certain areas. The "fake" model then has a method for creating a zip file. It seems to me that there has to be a better way to do this. I was wondering if there was a way to move the template into a .erb/haml file, and then write a method that would populate the file in preparation for being zipped up? Basically, is there a way to render an HTML and text file, without actually having to display them? Thanks for any help.

    Read the article

  • asp.net + How to create custom multi-templated tree databound control?

    - by ParagM
    I dont want to use asp.net's TreeView control. I want to create a custom template databound control with multi template support like - <asp:MtNavigationControl> <ItemTemplate> ... ... </ItemTemplate> <SelectedItemTemplate> ... ... </SelectedItemTemplate> <ParentItemTemplate> ... ... </ParentSelectedItemTemplate> <SelectedParentItemTemplate> ... ... </SelectedParentSelectedItemTemplate> </asp:MtNavigationControl> My data is like - class Employee { string EmployeeName List<Employee> Employees } Does anyone know how to accomplish it? Please help !!!

    Read the article

  • What are the standard practices for throwing JavasScript Exceptions?

    - by T.R.
    w3schools says that exceptions can be strings, integers, booleans, or objects, but the example given doesn't strike me as good practice, since exception type checking is done through string comparison. Is this the preferred method of exception handling in JavaScript? Are there built-in exception types (like NullPointerException)? (if so, what are they, what kind of inheritance do they use, and are they preferred over other options?)

    Read the article

  • Unable to pass attribute from controller to view

    - by MDS
    I'm using Spring MVC 3 for a web app. In the app a URI template is supposed to be handled by a controller method, which then passes an attribute to a view. Currently, the controller does handle the request, and it even forwards to the correct view. However, it does NOT pass the attribute to the view. Below are the URI template, controller method and relevent jsp tags. Anyone see what is wrong? URI: /home/{status} Controller: @RequestMapping("/home") @Controller public class HomeController { ... ... @RequestMapping(value="/{status}") public String homeStatusView(@PathVariable("status") String status, ModelMap model) { model.addAttribute("status", status); return "home"; } } JSP: ... <c:if test="${not empty status}"> <span class="status">Your status is available...</span> </c:if> ...

    Read the article

< Previous Page | 151 152 153 154 155 156 157 158 159 160 161 162  | Next Page >