Search Results

Search found 42453 results on 1699 pages for 'question'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 635/1699 | < Previous Page | 631 632 633 634 635 636 637 638 639 640 641 642  | Next Page >

  • C++ Virtual Constructor, without clone()

    - by Julien L.
    I want to perform "deep copies" of an STL container of pointers to polymorphic classes. I know about the Prototype design pattern, implemented by means of the Virtual Ctor Idiom, as explained in the C++ FAQ Lite, Item 20.8. It is simple and straightforward: struct ABC // Abstract Base Class { virtual ~ABC() {} virtual ABC * clone() = 0; }; struct D1 : public ABC { virtual D1 * clone() { return new D1( *this ); } // Covariant Return Type }; A deep copy is then: for( i = 0; i < oldVector.size(); ++i ) newVector.push_back( oldVector[i]->clone() ); Drawbacks As Andrei Alexandrescu states it: The clone() implementation must follow the same pattern in all derived classes; in spite of its repetitive structure, there is no reasonable way to automate defining the clone() member function (beyond macros, that is). Moreover, clients of ABC can possibly do something bad. (I mean, nothing prevents clients to do something bad, so, it will happen.) Better design? My question is: is there another way to make an abstract base class clonable without requiring derived classes to write clone-related code? (Helper class? Templates?) Following is my context. Hopefully, it will help understanding my question. I am designing a class hierarchy to perform operations on a class Image: struct ImgOp { virtual ~ImgOp() {} bool run( Image & ) = 0; }; Image operations are user-defined: clients of the class hierarchy will implement their own classes derived from ImgOp: struct CheckImageSize : public ImgOp { std::size_t w, h; bool run( Image &i ) { return w==i.width() && h==i.height(); } }; struct CheckImageResolution; struct RotateImage; ... Multiple operations can be performed sequentially on an image: bool do_operations( std::vector< ImgOp* > v, Image &i ) { std::for_each( v.begin(), v.end(), /* bind2nd(mem_fun(&ImgOp::run), i ...) don't remember syntax */ ); } int main( ... ) { std::vector< ImgOp* > v; v.push_back( new CheckImageSize ); v.push_back( new CheckImageResolution ); v.push_back( new RotateImage ); Image i; do_operations( v, i ); } If there are multiple images, the set can be split and shared over several threads. To ensure "thread-safety", each thread must have its own copy of all operation objects contained in v -- v becomes a prototype to be deep copied in each thread.

    Read the article

  • XmlDocument filter nodes by datetime string

    - by Eatdoku
    Trying to apply filter / attribute comparison in the Xmldocument. Obviously , the following code snippet wouldn't work because the expression can't be converted using number() function. (according to the answer of my other question). I'm wondering if there is a way to do the DateTime string comparison in XmlDoc. XmlNodeList test = x2PathDoc.SelectNodes("//Config /Entity [@TargetDateTime> '2010-12-19T03:25:00-08:00']");

    Read the article

  • Could my iPad app be denied from the app store for using the Tapku library?

    - by Dr Dork
    I'd like to use the Tapku library to add a calander date picker control to my iPad app. I'm new to iPhone OS development and I'm still rusty on identifying the 3rd party tools and code that will get my iPad app denied from the app store. For those that have used the Tapku library, would using it in my iPad app violate any app store rules? Thanks so much in advance for your help. I'm going to continue researching this question right now.

    Read the article

  • Expert R users, what's in your .Rprofile?...

    - by gappy
    This question is maybe a little too cute, but I have always found startup profile files of other people both useful and instructive about the language. Moreover, while I have some customization for bash and vim, I have nothing for R. For example, one thing I always wanted is different colors for input and output text in a window terminal, and maybe even syntax highlighting.

    Read the article

  • Synthesized property of a protocol not seeing superclass' ivar

    - by hyn
    I have a situation where my subclass is not seeing the superclass' instance variable x. The ivar is obviously @protected by default, so why do I get a compiler error "x undeclared"? - (CGSize)hitSize { // Compiler error return size; } EDIT: hitSize is a property of a protocol my subclass is conforming to. The problem was that I had hitSize @synthesized, which was the culprit. The question then is why can't the synthesized getter see the ivar?

    Read the article

  • Is there a way to use the OSX cocoa NSApplication method activateIgnoringOtherApps: to activate an a

    - by Michael Minerva
    This may be a dumb question but it seems like activateIgnoringOtherApps: may be the only way to activate an app using Cocoa. I have a java app that loads up a Cocoa app and I want the Cocoa app to be activated when this happens. The problem is I do not want to have to launch an intermediate app (some sort of controller) and use this app to activateIgnoringOtherApps: my other Cocoa app. Is there some way to use activateIgnoringOtherApps: to force my Cocoa app to become active?

    Read the article

  • Redirecting via .htaccess to .php with arguments in current folder.

    - by Jengerer
    Hey, I'm trying to redirect something like foo/bar to ?foo=bar, so I can do www.mydomain.com/hey/foo/bar to www.mydomain.com/hey/?foo=bar, but I can't seem to get the syntax right. I tried the following: RewriteEngine on RewriteRule ^foo/(.*)$ ?foo=bar [NC] But this doesn't work. How would I accomplish this? I tried adding a forward slash behind the question mark, but that makes it link to the root directory. Thanks, Jengerer

    Read the article

  • How Have You Implemented Open Source Contributions At Your Company?

    - by Travis
    Ok guys, I know others have asked this question in a similar manner in the past, but I want to go beyond the theoretical and find out answers from people who have worked in an environment that relied heavily upon open source technology and never contributed anything back to the open source community, and was able to convince the boss / owner to contribute back to the open source community. I know alot of the standard answers, but I'm looking for some more practical information? What was the key argument, that changed the culture in your company, and how has it changed?

    Read the article

  • Visual Studio .NET C# executable traces

    - by Chilln
    Hey, i've got a question, is it possible to identify the creator of a .NET assembly, just with traces from VisualStudio within the assembly ? Or can you even get a kind of unique ID of the creator out of it? I don't mean the application information like company or description, they can be edited too easily.

    Read the article

  • Does Windows CE support hash tables?

    - by Bryan
    Quick question of does Windows CE support hash tables? I have a program that I'm modifying and adding to a device that uses Windows CE and I was wondering if CE supported hash tables since it is used in the original software.

    Read the article

  • SQL Update help

    - by Cyborgo
    I have a really simple question, is it possible to update a table with new values using just one update statement. Say for example I have a table with author, title, date, popularity. Now I got some new data which has author name, title corresponding new popularity. How do I update the table now in one statement. Note that author and title are not unique.

    Read the article

  • SQL Injection When Using MySQLi Prepared Statements

    - by Sev
    If all that is used to do any and all database queries is MySQLi prepared statements with bound parameters in a web-app, is sql injection still possible? Notes I know that there are other forms of attack other than sql-injection, but my question is specific to sql-injection attacks on that particular web application only.

    Read the article

  • What does the "=>" mean?

    - by quakkels
    Hey SO, I've got a pretty noob question for ya. I keep seeing this syntax: <%= Html.LabelFor(model => model.Email) %> ...and I have no idea what the = means. I thought it was syntax for linq2sql or ado.net entity framework but I'm just using straight ado.net. I don't understand why the VWD used that syntax when generating the Create form. What does = mean?

    Read the article

  • Controlling QR Code Scanning Actions

    - by Elijah
    I am looking to create a QR code that does the following: When scanned from inside an application, it dislpays a custom alert, (Ex. "You won $5") When scanned with a different QR code reader (non app) it goes to a mobile web page that directs the user to download the application. My main question is: Can you control what happens when a QR code is scanned by a reader that is not your own? (A 'default' action, if you will)

    Read the article

  • Membership levels PHP

    - by Ben
    I want to make someone able to register on my site (or upgrade their current account) with one of 3 membership levels. When someone selects the membership level (or upgrades their current account) and registers, they will register under that membership level and payment will be started from there. My real question being how do I make someone able to sign up (or upgrade) an account upon registration (for new accounts) and upgrade for existing accounts and have this happen automatically so I dont have to do them all by hand? Thanks! Benjamin

    Read the article

  • How to select all parent objects into DataContext using single LINQ query ?

    - by too
    I am looking for an answer to a specific problem of fetching whole LINQ object hierarchy using single SELECT. At first I was trying to fill as much LINQ objects as possible using LoadOptions, but AFAIK this method allows only single table to be linked in one query using LoadWith. So I have invented a solution to forcibly set all parent objects of entity which of list is to be fetched, although there is a problem of multiple SELECTS going to database - a single query results in two SELECTS with the same parameters in the same LINQ context. For this question I have simplified this query to popular invoice example: public static class Extensions { public static IEnumerable<T> ForEach<T>(this IEnumerable<T> collection, Action<T> func) { foreach(var c in collection) { func(c); } return collection; } } public IEnumerable<Entry> GetResults(AppDataContext context, int CustomerId) { return ( from entry in context.Entries join invoice in context.Invoices on entry.EntryInvoiceId equals invoice.InvoiceId join period in context.Periods on invoice.InvoicePeriodId equals period.PeriodId // LEFT OUTER JOIN, store is not mandatory join store in context.Stores on entry.EntryStoreId equals store.StoreId into condStore from store in condStore.DefaultIfEmpty() where (invoice.InvoiceCustomerId = CustomerId) orderby entry.EntryPrice descending select new { Entry = entry, Invoice = invoice, Period = period, Store = store } ).ForEach(x => { x.Entry.Invoice = Invoice; x.Invoice.Period = Period; x.Entry.Store = Store; } ).Select(x => x.Entry); } When calling this function and traversing through result set, for example: var entries = GetResults(this.Context); int withoutStore = 0; foreach(var k in entries) { if(k.EntryStoreId == null) withoutStore++; } the resulting query to database looks like (single result is fetched): SELECT [t0].[EntryId], [t0].[EntryInvoiceId], [t0].[EntryStoreId], [t0].[EntryProductId], [t0].[EntryQuantity], [t0].[EntryPrice], [t1].[InvoiceId], [t1].[InvoiceCustomerId], [t1].[InvoiceDate], [t1].[InvoicePeriodId], [t2].[PeriodId], [t2].[PeriodName], [t2].[PeriodDateFrom], [t4].[StoreId], [t4].[StoreName] FROM [Entry] AS [t0] INNER JOIN [Invoice] AS [t1] ON [t0].[EntryInvoiceId] = [t1].[InvoiceId] INNER JOIN [Period] AS [t2] ON [t2].[PeriodId] = [t1].[InvoicePeriodId] LEFT OUTER JOIN ( SELECT 1 AS [test], [t3].[StoreId], [t3].[StoreName] FROM [Store] AS [t3] ) AS [t4] ON [t4].[StoreId] = ([t0].[EntryStoreId]) WHERE (([t1].[InvoiceCustomerId]) = @p0) ORDER BY [t0].[InvoicePrice] DESC -- @p0: Input Int (Size = 0; Prec = 0; Scale = 0) [186] -- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 3.5.30729.1 SELECT [t0].[EntryId], [t0].[EntryInvoiceId], [t0].[EntryStoreId], [t0].[EntryProductId], [t0].[EntryQuantity], [t0].[EntryPrice], [t1].[InvoiceId], [t1].[InvoiceCustomerId], [t1].[InvoiceDate], [t1].[InvoicePeriodId], [t2].[PeriodId], [t2].[PeriodName], [t2].[PeriodDateFrom], [t4].[StoreId], [t4].[StoreName] FROM [Entry] AS [t0] INNER JOIN [Invoice] AS [t1] ON [t0].[EntryInvoiceId] = [t1].[InvoiceId] INNER JOIN [Period] AS [t2] ON [t2].[PeriodId] = [t1].[InvoicePeriodId] LEFT OUTER JOIN ( SELECT 1 AS [test], [t3].[StoreId], [t3].[StoreName] FROM [Store] AS [t3] ) AS [t4] ON [t4].[StoreId] = ([t0].[EntryStoreId]) WHERE (([t1].[InvoiceCustomerId]) = @p0) ORDER BY [t0].[InvoicePrice] DESC -- @p0: Input Int (Size = 0; Prec = 0; Scale = 0) [186] -- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 3.5.30729.1 The question is why there are two queries and how can I fetch LINQ objects without such hacks?

    Read the article

  • How to encrypt information in aspx page?

    - by Jimmyc
    Hi all, I know it's a silly question but , My client asked for encrypting some information form their payment system to prevent user stealing personal information. The system is web-base and written by ASP.NET We have tried some annoying solution such as JavaScript no right-click or css-no-print but apparently my client didn't like it. so are there any commercial solution to encrypt information in aspx produced html pages? or someone can tell me how to pursuit my client to stop these "prevent stealing" idea in a web-base system?

    Read the article

  • How to set the returnURL manually when using Ajax.ActionLink

    - by Roge
    I have this link @Ajax.ActionLink("create poll question", "CreatePoll", new { id = Model.DebateID }, new AjaxOptions { UpdateTargetId = "poll-entry-box", InsertionMode = InsertionMode.Replace, HttpMethod = "GET" }) which is pointing at a action with the [Authorize] Attribute. The login works, but the returnURL is empty so it just redirects to the index page. Is there some way to manually set the returnURL ? NOTE I am using the method described here http://haacked.com/archive/2011/10/04/prevent-forms-authentication-login-page-redirect-when-you-donrsquot-want.aspx because the login page was loading inside my partial.

    Read the article

  • Undo "git add"?

    - by ceretullis
    Git newbie here, quick question. I mistakenly added files using the command "git add file". I have not yet run "git commit". Is there a way to remove these files from the commit?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 631 632 633 634 635 636 637 638 639 640 641 642  | Next Page >