Search Results

Search found 18464 results on 739 pages for 'virtual functions'.

Page 514/739 | < Previous Page | 510 511 512 513 514 515 516 517 518 519 520 521  | Next Page >

  • Is it possible to create thread-safe collections without locks?

    - by Andrey
    This is pure just for interest question, any sort of questions are welcome. So is it possible to create thread-safe collections without any locks? By locks I mean any thread synchronization mechanisms, including Mutex, Semaphore, and even Interlocked, all of them. Is it possible at user level, without calling system functions? Ok, may be implementation is not effective, i am interested in theoretical possibility. If not what is the minimum means to do it? EDIT: Why immutable collections don't work. This of class Stack with methods Add that returns another Stack. Now here is program: Stack stack = new ...; ThreadedMethod() { loop { //Do the loop stack = stack.Add(element); } } this expression stack = stack.Add(element) is not atomic, and you can overwrite new stack from other thread. Thanks, Andrey

    Read the article

  • Best .NET Framework compression class?

    - by Jack
    Hi all Yes, I know GZipStream or DeflateStream is the common ones in .NET Framework which handle compression/decompression. I wish to have compress/decompress functions in my program, but I wish a .NET Framework C# one, not a 3rd party open source. I can't use because of those copyright restrictions in my program. GZipStream and DeflateStream are not so good. for e.g., GZipStream compress a file to 480KB while 7Zip compress the same file to the size of 57KB. Does Microsoft have other good compression methods??? Thanks

    Read the article

  • How does jQuery store data with .data()?

    - by TK
    I am a little confused how jQuery stores data with .data() functions. Is this something called expando? Or is this using HTML5 Web Storage although I think this is very unlikely? The documentation says: The .data() method allows us to attach data of any type to DOM elements in a way that is safe from circular references and therefore from memory leaks. As I read about expando, it seems to have a rick of memory leak. Unfortunately my skills are not enough to read and understand jQuery code itself, but I want to know how jQuery stores such data by using data(). http://api.jquery.com/data/

    Read the article

  • Weird use of generics

    - by Karl Trumstedt
    After a bit of programming one of my classes used generics in a way I never seen before. I would like some opinions of this, if it's bad coding or not. abstract class Base<T> : where T : Base<T> { // omitted methods and properties. virtual void CopyTo(T instance) { /*code*/ } } class Derived : Base<Derived> { override void CopyTo(Derived instance) { base.CopyTo(instance); // copy remaining stuff here } } is this an OK use of generics or not? I'm mostly thinking about the constraint to "itself". I sometimes feel like generics can "explode" to other classes where I use the Base class.

    Read the article

  • Obtaining references to function objects on the execution stack from the frame object?

    - by Marcin
    Given the output of inspect.stack(), is it possible to get the function objects from anywhere from the stack frame and call these? If so, how? (I already know how to get the names of the functions.) Here is what I'm getting at: Let's say I'm a function and I'm trying to determine if my caller is a generator or a regular function? I need to call inspect.isgeneratorfunction() on the function object. And how do you figure out who called you? inspect.stack(), right? So if I can somehow put those together, I'll have the answer to my question. Perhaps there is an easier way to do this?

    Read the article

  • Define cursor on element

    - by sanceray3
    Hi all, I try to explain my problem. I have a <div contenteditable="true" id="my_editeur>, where I have defined a keypress “event” which allow me to add a ‘p’ when the user clicks on “enter”. It functions well, but I would like define the cursor on this new ‘p’ element, because currently my cursor stays on the first 'p' element. I have tried to use jquery focus function but it seems that we can’t use this function for ‘p’ elements. Do you know how I can do to solve my problem? Thanks very much for your help. My code : $('#my_editeur').keypress(function(e){ if(e.keyCode == 13) { e.preventDefault(); $(this).append('<p ><br /></p>'); } });

    Read the article

  • Copying a Polymorphic object in C++

    - by doron
    I have base-class Base from which is derived Derived1, Derived2 and Derived3. I have constructed an instance for one of the the derived classes which I store as Base* a. I now need to make a deep copy of the object which I will store as Base* b. As far as I know, the normal way of copying a class is to use copy constructors and to overload operator=. However since I don't know whether a is of type Derived1, Derived2 or Derived3, I cannot think of a way of using either the copy constructor or operator=. The only way I can think of to cleanly make this work is to implement something like: class Base { public: virtual Base* Clone() = 0; }; and the implement Clone in in the derived class as in: class Derivedn : public Base { public: Base* Clone() { Derived1* ret = new Derived1; copy all the data members } }; Java tends to use Clone quite a bit is there more of a C++ way of doing this?

    Read the article

  • How to make scipy.interpolate give a an extrapolated result beyond the input range?

    - by Salim Fadhley
    I'm trying to port a program which uses a hand-rolled interpolator (developed by a mathematitian colleage) over to use the interpolators provided by scipy. I'd like to use or wrap the scipy interpolator so that it has as close as possible behavior to the old interpolator. A key difference between the two functions is that in our original interpolator - if the input value is above or below the input range, our original interpolator will extrapolate the result. If you try this with the scipy interpolator it raises a ValueError. Consider this program as an example: import numpy as np from scipy import interpolate x = np.arange(0,10) y = np.exp(-x/3.0) f = interpolate.interp1d(x, y) print f(9) print f(11) # Causes ValueError, because it's greater than max(x) Is there a sensible way to make it so that instead of crashing, the final line will simply do a linear extrapolate, continuing the gradients defined by the first and last two pouints to infinity. Note, that in the real software I'm not actually using the exp function - that's here for illustration only!

    Read the article

  • Small Python optional arguments question

    - by ooboo
    I have two functions: def f(a,b,c=g(b)): blabla def g(n): blabla c is an optional argument in function f. If the user does not specify its value, the program should compute g(b) and that would be the value of c. But the code does not compile - it says name 'b' is not defined. How to fix that? Someone suggested: def g(b): blabla def f(a,b,c=None): if c is None: c = g(b) blabla But this doesn't work, because maybe the user intended c to be None and then c will have another value.

    Read the article

  • Is there a way to add an elmah rss feed to google reader?

    - by Jason Irwin
    Elmah has an rss feed and rss digest feature. My feeds are working just fine from within my brwoser. However I would like to add them to google reader as this is my feed reader of choice. The problem is that Elmah uses an AXD handler to server its information - therefore the path to the RSS feed is not a physical one. For example the RSS feed for my site is located at: http://www.mysite.com/errors/elmah.axd/rss This is not a file nor does the folder structure exist - it is all part of the beauty of Elmah. When I attempt to add this virtual path as a feed in google reader i get: Your search did not match any feeds Any help would be greatly appreciated, Thanks Jason

    Read the article

  • ACCESS 2003 Excel 2003 : VBA for opening Excel file from Access and copying a pictre from excel the

    - by Justin
    So I have an excel workbook that has a nice global map of shaperange objects. With some very simple code I can change the colors, group and ungroup collections of countries into arrays, etc...and it works pretty well. However, I would like to bring this into Access. So I could copy and paste all the shapes into an access form manually, but then they become pictures and I cannot change the colors of the countries (shaperange objects) to have the map act interactively as I can in excel. So I am thinking that I know how to use excel functions from access, and how to open excel from access. Is there a way to copy an object from excel (I know the file name and the shape name that i mean to copy everytime), and bringing it back to access to paste on a form? Atypical, I know, all my Access questions are. Thanks!

    Read the article

  • How to convert a function that returns a int to a function that returns a bool using boost::bind?

    - by user814628
    I have something like the following: struct A{ virtual int derp(){ if(herp()) return 1; else return 0; } void slurp(){ boost::function<bool(int x, int y> purp = /** boost bind derp to match lvalue sig **/; } } Any ideas? I want to create the function prup which basically calls derp and ignores the (x,y) passed in. I need something like bool purp(int x, int y){ return derp(); } but want to avoid creating it as a member function, and rather just create it locally if possible?

    Read the article

  • CLR Function not working in restored database

    - by Ben Thul
    So I've restore a database with CLR assemblies in it from one physical server to another. One of the functions in the CLR assembly essentially does an uncompress of some compressed data. When I run this function against data in the restored database it returns the compressed data (rather than the uncompressed data). No error is thrown in SSMS or in the SQL server error logs. At the suggestion of others, I've checked differences in the database ownership (both owned by sa), trustworthiness (both set to not trustworthy). I also checked differences in the .NET framework installs on both machines but found only that the target machine had a 1.1 version installed that the source didn't. I don't know what else to try. Any suggestions would be most appreciated. Thanks in advance. Thanks in advance, Ben

    Read the article

  • Data-separation in a Symfony Multi-tenant app using Doctrine

    - by Prasad
    I am trying to implement a multi-tenant application, that is - data of all clients in a single database - each shared table has a tenant_id field to separate data I wish to achieve data separation by adding where('tenant_id = ', $user->getTenantID()) {pseudoc-code} to all SELECT queries I could not find any solution up-front, but here are possible approaches I am considering. 1) crude approach: customizing all fetchAll and fetchOne functions in every class (I will go mad!) 2) using listeners: possibly coding for the preDqlSelect event and adding the 'where' to all queries 3) override buildQuery(): could not find an example of this for front-end 4) implement contentformfilter: again need a pointer Would appreciate if someone could validate these & comment on efficieny, suitability. Also, if anyone has achieved multitenancy using another strategy, pl share. Thanks

    Read the article

  • Capture String from Array, C#

    - by Dan Snyder
    I'm trying to figure out how to get a string from an array starting at some given position. Say we have an array that's arbitrarily long and my string starts at location 1000. If I wanted to get a string from a file I would simply use something like getc or scanf or something. How do I carry out these same functions on an array instead of a file? *oh, keep in mind that the array is of type int and is full of numerical representations of ASCII characters.

    Read the article

  • Are multiline tooltips possible using CWnd::EnableTooltips()?

    - by ctoneal
    I'm attempting to make my tooltips multiline, but I don't seem to be having much luck with it. I call CWnd::EnableTooltips() directly after creation (in this case, an edit box) and I handle the TTN_NEEDTEXT message. My tooltips display correctly, but only display as a single line. I've tried adding '\n' to the string I pass when handling TTN_NEEDTEXT, and also tried '\r\n'. No luck. It just displays them as normal text in the tooltip string. I then tried manually inserting 0x0D0A, but this just displays as boxes. I've been digging a bit, and have found a few offhand references on the web saying that multiline behavior may not work when using tooltips through the CWnd functions. I'd prefer not to have to replace with CToolTipCtrl (since it's a rather large project). Has anyone ran into this before? If so, is there any way around it?

    Read the article

  • Microsoft _stprintf warning

    - by mnh
    Why I get the following warning for the following code :) Code: _stprintf(m_szFileNamePath,_T("%s"),strFileName); warning C4996: '_swprintf': swprintf has been changed to conform with the ISO C standard, adding an extra character count parameter. To use traditional Microsoft swprintf, set _CRT_NON_CONFORMING_SWPRINTFS. I know _strprintf is a macro which if _UNICODE is defined will evaluate to _swprintf else it will be sprintf. Now what is this _swprintf. There is a function swprintf, but why is _stprintf evaluating to _swprintf instead of swprintf. What is the difference b/w the _xxx and xxx functions? EDIT: Okay there are two definitions for the UNICODE version of _stprintf, which one is included? The one in tchar.h or strsafe.h?

    Read the article

  • FORTRAN function returning an array causes a segfault (calling from C++)

    - by Dane Larsen
    Basically, here's my problem. I'm calling someone else's FORTRAN functions from my C++ code, and it's giving me headaches. Some code: function c_error_message() character(len = 255) :: c_error_message errmsg(1:9) = 'ERROR MSG' return end That's the FORTRAN function. My first question is: Is there anything in there that would cause a segfault? If not, then second: What does that return? A pointer? I'm trying to call it with the following C statement: char *e = c_error_message_(); That causes a segfault. c_error_message(); That too causes a segfault. I declared c_error_message_() earlier on with the following code: extern"C" { char* c_error_message_(); } Would declaring a function with a different return type than the actual return type cause a segfault? I'm at a loss. Thanks for any replies.

    Read the article

  • ASP.NET (VB) - Close an opened SQL connection inside Function

    - by B1GB0Y
    Can anyone tell me how I close an opened SQL connection inside a Function? I call a Select Function like this: Function Selec(ByVal SQLStr As String) As SqlDataReader Dim SQLConn As New SqlConnection() Dim SQLCmd As New SqlCommand() SQLConn.ConnectionString = Session("bd") SQLConn.Open() SQLCmd.Connection = SQLConn SQLCmd.CommandText = SQLStr Selec = SQLCmd.ExecuteReader End Function And in another page I do a While method to retrieve me the data like this: (Note: BDcon.BD is the name of the Class that have Functions) Dim write as New BDcon.BD Dim menu As SqlDataReader = writeBD.Selec("SELECT something from Table") While menu.Read 'Do something End While menu.Close 'This close just the DataReader and not the SqlConnection Finally I want to Close my SQL Connection by Function like this: Function Close() As SqlConnection Dim SQLConn As New SqlConnection() SQLConn.ConnectionString = Session("bd") SQLConn.Close() End Function I think that the problem is on the Close() Function, I want to close the connection but I don't know how to call my Opened Conneciton. Please anyone can help me? Thanks in advance :)

    Read the article

  • Django says the "id may not be NULL" but why is it?

    - by Oli
    I'm going crazy today. I just tried to insert a new record and it threw back a "post_blogpost.id may not be NULL" error. Here's my model: class BlogPost(models.Model): title = models.CharField(max_length=100) slug = models.SlugField(max_length=100) who = models.ForeignKey(User, default=1) when = models.DateTimeField() intro = models.TextField(blank=True, null=True) content = models.TextField(blank=True, null=True) counter = models.PositiveIntegerField(default=0) published = models.BooleanField(default=False) css = models.TextField(blank=True, null=True) class Meta: ordering = ('-when', 'id') There are a number of functions beneath the model too but I won't include them in full here. Their names are: content_cache_key, clear_cache, __unicode__, reads, read, processed_content. I'm adding through the admin... And I'm running out of hair.

    Read the article

  • Sparx Enterprise Architect conversion (from source to UML)

    - by user228938
    I need to make a UML class diagram for a project. I used Sparx Enterprise Architect in the past to generate source code from a diagram so I'm using that. The project is complete so all of the code is done and I don't really want to write all the classes / functions manually, so I was trying to generate the diagram from the source code but can't seem to find a way to do it. I searched online and on their website but nothing. Any help appreciated. Thanks in advance.

    Read the article

  • cheap way to scale a rails application

    - by VP
    I have an application, that is becoming big, but until now, its not giving me a good revenue. That means, short money to re-invest on that. In this scenario, i found a way to make a "cheap distributed rails" deployment. I've got 4 VPS. All of them are in the same physical server. I added a load balance server running HAproxy in one dedicated VPS. There i pointed my virtual ip address where my domain name is associated. Behind this HAproxy i have more two VPS running my rails APP, passenger and memcache. Both apps servers are looking to the same database server, my 4th VPS. So with $44/month, i mounted a distributed environment. It won't be my final choice, but now, that the budget is short, is that a good way to deploy a rails application? Any pros or cons? It worth my $44/month?

    Read the article

  • Removing WS_BORDER and WS_CAPTION from windows styles doesn't work

    - by lordfrikk
    Hello, I created a small app in C# that removes border and caption from window, then it sets size to the user's resolution and centers it. It's a utility for me to use when I want to play games in windowed mode without being annoyed by the borders. Everything works fine with most games, but I tried to use it on a recently released game Alpha Protocol and it doesn't work. I could almost say that the game reverts my changes, but I'm not sure how to tell if that's true or not. I'm using imported API functions MoveWindow, SetWindowLong and SetWindowPos. Snippet: Win32.MoveWindow(hWnd, 0, 0, Convert.ToInt32(sizeXText.Text), Convert.ToInt32(sizeYText.Text), true); Win32.SetWindowLong(hWnd, GWL_STYLE, Win32.GetWindowLong(hWnd, GWL_STYLE) & ~WS_CAPTION & ~WS_BORDER); Win32.SetWindowPos(hWnd, 0, 0, 0, 0, SWP_NOZORDER|SWP_NOMOVE|SWP_NOSIZE|SWP_NOACTIVATE|SWP_DRAWFRAME);

    Read the article

  • how to invoke function writen in a validation.php and stroe all function name in database.

    - by saint
    Respected all, i'm in trouble. I created a file with name validation.php and store all my validation functionality in this file with different function names like, check_textbox(parm1, pram2, pram3, pram4) { // Definition here } check_chkBox(parm1, pram2) { // Definition here } and so on.....! then i created a table in mysql with the name tbValidation and stored all the function name with parameters in a table. the record stored in table look like as: interfaceid---------- functionNameWithReturnValue 1 ------------ check_textbox(parm1, pram2, pram3, pram4) = 1 2 ------------ check_textbox(parm1, pram2, pram4) = 0 3 ------------ check_textbox(parm1, pram2, pram4) = 1) AND (check_chkBox(parm1, pram2)=0) when i fetch record from database i want to invoke those functions that store in validation.php $data = mysql_fetch_array($drow); if($db->row_count > 0) { // when i fetch row one from database. I used this one but not working // @ $data[0] have value "check_textbox(parm1, pram2, pram3, pram4) = 1" if($data[0]) { // Do this } } How i can do this task...? :(

    Read the article

  • SQL Server Query Slow from PHP, but FAST from SQL Mgt Studio - WHY???

    - by Ray
    I have a fast running query (sub 1 sec) when I execute the query in SQL Server Mgt Studio, but when I run the exact same query in PHP (on the same db instace) using FreeTDS v8, mssql_query(), it takes much longer (70+ seconds). The tables I'm hitting have an index on a date field that I'm using in the Where clause. Could it be that PHP's mssql functions aren't utilizing the index? I have also tried putting the query inside a stored procedure, then executing the SP from PHP - the same results in time difference occurs. I have also tried adding a WITH ( INDEX( .. ) ) clause on the table where that has the date index, but no luck either. Here's the query: SELECT 1 History, h.CUSTNMBR CustNmbr, CONVERT(VARCHAR(10), h.ORDRDATE, 120 ) OrdDate, h.SOPNUMBE OrdNmbr, h.SUBTOTAL OrdTotal, h.CSTPONBR PONmbr, h.SHIPMTHD Shipper, h.VOIDSTTS VoidStatus, h.BACHNUMB BatchNmbr, h.MODIFDT ModifDt FROM SOP30200 h WITH (INDEX (AK2SOP30200)) WHERE h.SOPTYPE = 2 AND h.DOCDATE >= DATEADD(dd, -61, GETDATE()) AND h.VOIDSTTS = 0 AND h.MODIFDT = CONVERT(VARCHAR(10), DATEADD(dd, -1*@daysAgo, GETDATE()) , 120 ) ;

    Read the article

< Previous Page | 510 511 512 513 514 515 516 517 518 519 520 521  | Next Page >