Search Results

Search found 36506 results on 1461 pages for 'unsigned long long int'.

Page 488/1461 | < Previous Page | 484 485 486 487 488 489 490 491 492 493 494 495  | Next Page >

• Histogram matching - image processing - c/c++

  - by Raj

  Hello I have two histograms. int Hist1[10] = {1,4,3,5,2,5,4,6,3,2}; int Hist1[10] = {1,4,3,15,12,15,4,6,3,2}; Hist1's distribution is of type multi-modal; Hist2's distribution is of type uni-modal with single prominent peak. My questions are Is there any way that i could determine the type of distribution programmatically? How to quantify whether these two histograms are similar/dissimilar? Thanks

  Read the article

• Detecting Infinite recursion in Python or dynamic languages

  - by drozzy

  Recently I tried compiling program something like this with GCC: int f(int i){ if(i<0){ return 0;} return f(i-1); and it ran just fine. When I inspected the stack frames the compiler optimized the program to use only one frame, by just jumping back to the beginning of the function and only replacing the arguments to f. And - the compiler wasn't even running in optimized mode. Now, when I try the same thing in Python - I hit maximum recursion wall (or stack overflow). Is there way that a dynamic language like python can take advantage of these nice optimizations? Maybe it's possible to use a compiler instead of an interpreter to make this work? Just curious!

  Read the article

• Can't get my head arround background workers in c#

  - by Connel

  I have wrote an application that syncs two folders together. The problem with the program is that it stops responding whilst copying files. A quick search of stack-overflow told me I need to use something called a background worker. I have read a few pages on the net about this but find it really hard to understand as I'm pretty new to programming. Below is the code for my application - how can I simply put all of the File.Copy(....) commands into their own background worker (if that's even how it works)? Below is the code for the button click event that runs the sub procedure and the sub procedure I wish to use a background worker on all the File.Copy lines. Button event: protected virtual void OnBtnSyncClicked (object sender, System.EventArgs e) { //sets running boolean to true booRunning=true; //sets progress bar to 0 prgProgressBar.Fraction = 0; //resets values used by progressbar dblCurrentStatus = 0; dblFolderSize = 0; //tests if user has entered the same folder for both target and destination if (fchDestination.CurrentFolder == fchTarget.CurrentFolder) { //creates message box MessageDialog msdSame = new MessageDialog(this, DialogFlags.Modal, MessageType.Error, ButtonsType.Close, "You cannot sync two folders that are the same"); //sets message box title msdSame.Title="Error"; //sets respone type ResponseType response = (ResponseType) msdSame.Run(); //if user clicks on close button or closes window then close message box if (response == ResponseType.Close || response == ResponseType.DeleteEvent) { msdSame.Destroy(); } return; } //tests if user has entered a target folder that is an extension of the destination folder // or if user has entered a desatination folder that is an extension of the target folder if (fchTarget.CurrentFolder.StartsWith(fchDestination.CurrentFolder) || fchDestination.CurrentFolder.StartsWith(fchTarget.CurrentFolder)) { //creates message box MessageDialog msdContains = new MessageDialog(this, DialogFlags.Modal, MessageType.Error, ButtonsType.Close, "You cannot sync a folder with one of its parent folders"); //sets message box title msdContains.Title="Error"; //sets respone type and runs message box ResponseType response = (ResponseType) msdContains.Run(); //if user clicks on close button or closes window then close message box if (response == ResponseType.Close || response == ResponseType.DeleteEvent) { msdContains.Destroy(); } return; } //gets folder size of target folder FileSizeOfTarget(fchTarget.CurrentFolder); //gets folder size of destination folder FileSizeOfDestination(fchDestination.CurrentFolder); //runs SyncTarget procedure SyncTarget(fchTarget.CurrentFolder); //runs SyncDestination procedure SyncDestination(fchDestination.CurrentFolder); //informs user process is complete prgProgressBar.Text = "Finished"; //sets running bool to false booRunning = false; } Sync sub-procedure: protected void SyncTarget (string strCurrentDirectory) { //string array of all the directories in directory string[] staAllDirectories = Directory.GetDirectories(strCurrentDirectory); //string array of all the files in directory string[] staAllFiles = Directory.GetFiles(strCurrentDirectory); //loop over each file in directory foreach (string strFile in staAllFiles) { //string of just the file's name and not its path string strFileName = System.IO.Path.GetFileName(strFile); //string containing directory in target folder string strDirectoryInsideTarget = System.IO.Path.GetDirectoryName(strFile).Substring(fchTarget.CurrentFolder.Length); //inform user as to what file is being copied prgProgressBar.Text="Syncing " + strFile; //tests if file does not exist in destination folder if (!File.Exists(fchDestination.CurrentFolder + "/" + strDirectoryInsideTarget + "/" + strFileName)) { //if file does not exist copy it to destination folder, the true below means overwrite if file already exists File.Copy (strFile, fchDestination.CurrentFolder + "/" + strDirectoryInsideTarget + "/" + strFileName, true); } //tests if file does exist in destination folder if (File.Exists(fchDestination.CurrentFolder + "/" + strDirectoryInsideTarget + "/" + strFileName)) { //long (number) that contains date of last write time of target file long lngTargetFileDate = File.GetLastWriteTime(strFile).ToFileTime(); //long (number) that contains date of last write time of destination file long lngDestinationFileDate = File.GetLastWriteTime(fchDestination.CurrentFolder + "/" + strDirectoryInsideTarget + "/" + strFileName).ToFileTime(); //tests if target file is newer than destination file if (lngTargetFileDate > lngDestinationFileDate) { //if it is newer then copy file from target folder to destination folder File.Copy (strFile, fchDestination.CurrentFolder + "/" + strDirectoryInsideTarget + "/" + strFileName, true); } } //gets current file size FileInfo FileSize = new FileInfo(strFile); //sets file's filesize to dblCurrentStatus and adds it to current total of files dblCurrentStatus = dblCurrentStatus + FileSize.Length; double dblPercentage = dblCurrentStatus/dblFolderSize; prgProgressBar.Fraction = dblPercentage; } //loop over each folder in target folder foreach (string strDirectory in staAllDirectories) { //string containing directories inside target folder but not any higher directories string strDirectoryInsideTarget = strDirectory.Substring(fchTarget.CurrentFolder.Length); //tests if directory does not exist inside destination folder if (!Directory.Exists(fchDestination.CurrentFolder + "/" + strDirectoryInsideTarget)) { //it directory does not exisit create it Directory.CreateDirectory(fchDestination.CurrentFolder + "/" + strDirectoryInsideTarget); } //run sync on all files in directory SyncTarget(strDirectory); } } Any help will be greatly appreciated as after this the program will pretty much be finished :D

  Read the article

• Create WPF TextBox that accepts only numbers

  - by Elad

  I would like to create a TextBox that only accepts numeric values, in a specific range. What is the best way to implement such TextBox? I thought about deriving TextBox and to override the validation and coercion of the TextProperty. However, I am not sure how to do this, and I understand that deriving WPF control is generally not recommended. Edit: What I needed was a very basic textbox that filters out all key presses which are not digits. The easiest way to achieve it is to handle the TextBox.PreviewTextInput event: private void textBox_PreviewTextInput(object sender, TextCompositionEventArgs e) { int result; if (!validateStringAsNumber(e.Text,out result,false)) { e.Handled = true; } } (validateStringAsNumber is my function that primarily use Int.TryParse) Some of the suggested solutions are probably better, but for the simple functionality I needed this solution is the easiest and quickest to implement while sufficient for my needs.

  Read the article

• Providing localized error messages for non-attributed model validation in ASP.Net MVC 2?

  - by Lance McNearney

  I'm using the DataAnnotations attributes along with ASP.Net MVC 2 to provide model validation for my ViewModels: public class ExamplePersonViewModel { [Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(Resources.Validation))] [StringLength(128, ErrorMessageResourceName = "StringLength", ErrorMessageResourceType = typeof(Resources.Validation))] [DataType(DataType.Text)] public string Name { get; set; } [Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(Resources.Validation))] [DataType(DataType.Text)] public int Age { get; set; } } This seems to work as expected (although it's very verbose). The problem I have is that there are behind-the-scenes model validations being performed that are not tied to any specific attribute. An example of this in the above model is that the Age property needs to be an int. If you try to enter a non-integer value on the form, it will error with the following (non-localized) message: The field Age must be a number. How can these non-attribute validation messages be localized? Is there a full list of these messages available so I can make sure they are all localized?

  Read the article

• SML/NJ incomplete match

  - by dimvar

  I wonder how people handle nonexhaustive match warnings in the SML/NJ compiler. For example, I may define a datatype datatype DT = FOO of int | BAR of string and then have a function that I know only takes FOOs fun baz (FOO n) = n + 1 The compiler will give a warning stdIn:1.5-1.24 Warning: match nonexhaustive FOO n = ... val baz = fn : DT - int I don't wanna see warnings for incomplete matches I did on purpose, because then I have to scan through the output to find a warning that might actually be a bug. I can write the function like this fun baz (FOO n) = n + 1 | baz _ = raise Fail "baz" but this clutters the code. What do people usually do in this situation?

  Read the article

• Agilent E4426B signal generator locks up during multiple GPIB *SAV operations

  - by aspiehler

  I have a test fixture with an Agilent E4426B RF signal generator connected to a PC via a National Instrument Ethernet-to-GPIB bridge. My software is attempting to sanitize the instrument by presetting it and then saving the current state to all of the memory locations writable via the standard SCPI command "*SAV x,y". The loop works to a point, but eventually the instrument responds with an error and continuously displays the "L" icon on the front display and a "Remote preset" message at the bottom. At that point it won't respond to any more remote commands and I have to either cycle power or press LOCAL, then PRESET at which point it takes about 3 minutes to finish presetting. At that point the "L" icon is still present and and the next GPIB command sent to the instrument causes it to report a -113 error (undefined header) in the instrument error queue. I fired up NI spy to see what was happening, and found that the error was happening at the same point in the loop - "*SAV 6,2" in this case. From NI Spy: Send (0, 0x0017, "*SAV 6,2", 8 (0x8), NLend (0,0x01)) Process ID: 0x00000520 Thread ID: 0x00000518 ibsta:0xc168 iberr: 6 ibcntl: 2(0x2) And here's the code from the instrument driver: int CHP_E4426b::Erase() { if ((m_StatusCode = Initialize()) != GPIB_SUCCESS) // basically just sends "*RST" return m_StatusCode; m_SaveState = "*SAV %d, %d"; for (int i=0; i < 10; i++) for (int j=0; j < 100; j++) { sprintf(m_CmdString, m_SaveState, j, i); if ((m_StatusCode = Send(m_CmdString, strlen(m_CmdString))) != GPIB_SUCCESS) return m_StatusCode; } return GPIB_SUCCESS; } I tried putting a small Sleep() delay (10-20 ms) at the end of the inner loop, and to my surprise it caused the error to show up earlier rather than later. 10 ms caused the loop to error out at 44,1 and 20 ms was even sooner. I've already eliminated faulty cabling or the instrument as the culprit. This same type of sequence works without any error on a higher end signal generator, so I'm tempted to chalk this up to a bug in the instrument's firmware.

  Read the article

• c# inheriting generic collection and serialization...

  - by Stecy

  Hi, The setup: class Item { private int _value; public Item() { _value = 0; } public int Value { get { return _value; } set { _value = value; } } } class ItemCollection : Collection<Item> { private string _name; public ItemCollection() { _name = string.Empty; } public string Name { get {return _name;} set {_name = value;} } } Now, trying to serialize using the following code fragment: ItemCollection items = new ItemCollection(); ... XmlSerializer serializer = new XmlSerializer(typeof(ItemCollection)); using (FileStream f = File.Create(fileName)) serializer.Serialize(f, items); Upon looking at the resulting XML I see that the ItemCollection.Name value is not there! I think what may be happening is that the serializer sees the ItemCollection type as a simple Collection thus ignoring any other added properties... Is there anyone having encountered such a problem and found a solution? Regards, Stécy

  Read the article

• IE8 BHO tab problem

  - by simil

  I am developing an IE8 BHO in C#. One of the functions of the BHO is to maintain a list of website pairs visited by the user. I add the pair (url1, url2) to the list if the user visits url2 by clicking on a link present at url1. I will be using this info to show the ie history in a nice way as opposed to the default behaviour of showing a long list of visited websites (something along the lines of the Firefox addon Voyage ). In my BHO, I am currently using the BeforeNavigate2 event to find the URL the user is going to visit. This works fine as long as the page is opened in the same tab. But, how to find if the user opens the link in a new tab/new window? Is there a way (other than IPC) in which we can find the url from which the user came from? Thanks, simil

  Read the article

• LevelToVisibilityConverter in silverligt 4

  - by prince23

  <UserControl x:Class="SLGridImage.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="400" xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"> <UserControl.Resources> <local:LevelToVisibilityConverter x:Key="LevelToVisibility" /> </UserControl.Resources> <Grid x:Name="LayoutRoot" Background="White"> <sdk:DataGrid x:Name="dgMarks" CanUserResizeColumns="False" SelectionMode="Single" AutoGenerateColumns="False" VerticalAlignment="Top" ItemsSource="{Binding MarkCollection}" IsReadOnly="True" Margin="13,44,0,0" RowDetailsVisibilityMode="Collapsed" Height="391" HorizontalAlignment="Left" Width="965" VerticalScrollBarVisibility="Visible" > <sdk:DataGrid.Columns> <sdk:DataGridTemplateColumn> <sdk:DataGridTemplateColumn.CellTemplate> <DataTemplate> <Button x:Name="myButton" Click="myButton_Click"> <StackPanel Orientation="Horizontal"> <Image Margin="2, 2, 2, 2" x:Name="imgMarks" Stretch="Fill" Width="12" Height="12" Source="Images/test.png" VerticalAlignment="Center" HorizontalAlignment="Center" Visibility="{Binding Level, Converter={StaticResource LevelToVisibility}}" /> <TextBlock Text="{Binding Level}" TextWrapping="NoWrap" ></TextBlock> </StackPanel> </Button> </DataTemplate> </sdk:DataGridTemplateColumn.CellTemplate> </sdk:DataGridTemplateColumn> <sdk:DataGridTemplateColumn Header="Name" > <sdk:DataGridTemplateColumn.CellTemplate> <DataTemplate > <Border> <TextBlock Text="{Binding Name}" /> </Border> </DataTemplate> </sdk:DataGridTemplateColumn.CellTemplate> </sdk:DataGridTemplateColumn> <sdk:DataGridTemplateColumn Header="Marks" Width="80"> <sdk:DataGridTemplateColumn.CellTemplate> <DataTemplate> <Border> <TextBlock Text="{Binding Marks}" /> </Border> </DataTemplate> </sdk:DataGridTemplateColumn.CellTemplate> </sdk:DataGridTemplateColumn> </sdk:DataGrid.Columns> </sdk:DataGrid> </Grid> </UserControl> in .cs using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; using System.Collections.ObjectModel; using System.ComponentModel; namespace SLGridImage { public partial class MainPage : UserControl { private MarksViewModel model = new MarksViewModel(); public MainPage() { InitializeComponent(); this.DataContext = model; } private void myButton_Click(object sender, RoutedEventArgs e) { } } public class MarksViewModel : INotifyPropertyChanged { public MarksViewModel() { markCollection.Add(new Mark() { Name = "ABC", Marks = 23, Level = 0 }); markCollection.Add(new Mark() { Name = "XYZ", Marks = 67, Level = 1 }); markCollection.Add(new Mark() { Name = "YU", Marks = 56, Level = 0 }); markCollection.Add(new Mark() { Name = "AAA", Marks = 89, Level = 1 }); } private ObservableCollection<Mark> markCollection = new ObservableCollection<Mark>(); public ObservableCollection<Mark> MarkCollection { get { return this.markCollection; } set { this.markCollection = value; OnPropertyChanged("MarkCollection"); } } public event PropertyChangedEventHandler PropertyChanged; public void OnPropertyChanged(string propName) { if (PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(propName)); } } public class Mark { public string Name { get; set; } public int Marks { get; set; } public int Level { get; set; } } public class LevelToVisibilityConverter : System.Windows.Data.IValueConverter { #region IValueConverter Members public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { Visibility isVisible = Visibility.Collapsed; if ((value == null)) return isVisible; int condition = (int)value; isVisible = condition == 1 ? Visibility.Visible : Visibility.Collapsed; return isVisible; } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { throw new NotImplementedException(); } #endregion } } when i run getting error The type 'local:LevelToVisibilityConverter' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built. what i am i missing here looking forward for an solution thank you

  Read the article

• LINQ-to-SQL Query Timing Out

  - by kevinw

  I'm running this query in LINQ: var unalloc = db.slot_sp_getUnallocatedJobs("Repair", RadComboBox1.SelectedValue, 20); It runs when I first open the page, but when I go back to it and try to run the same query with a different value, "Con", being passed through, the linq to sql designer.cs tells me that I've got a timeout error. Any ideas? Edit: This is what's in the designer: [Function(Name="dbo.slot_sp_getUnallocatedJobs")] Public ISingleResult<slot_sp_getUnallocatedJobsResult> slot_sp_getUnallocatedJobs([Parameter(Name="JobType", DbType="VarChar(20)")] string jobType, [Parameter(Name="Contract", DbType="VarChar(10)")] string contract, [Parameter(Name="Num", DbType="Int")] System.Nullable<int> num) { IExecuteResult result = this.ExecuteMethodCall(this, ((MethodInfo)(MethodInfo.GetCurrentMethod())), jobType, contract, num); return ((ISingleResult<slot_sp_getUnallocatedJobsResult>)(result.ReturnValue)); } } This is the error: SQLException was unhandled by user code Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

  Read the article

• Why C# calls different overloaded method for different values of same type?

  - by Fabio Veronez

  Hello all, I have one doubt concerning c# method overloading call resolution. Let's suppose I have the following C# code: enum MyEnum { Value1, Value2 } public void test() { method(0); // this calls method(MyEnum) method(1); // this calls method(object) } public void method(object o) { } public void method(MyEnum e) { } Note that I know how to make it work but I would like to know why for one value of int (0) it calls one method and for another (1) it calls another. It sounds awkward since both values have the same type (int) but they are "linked" for different methods. Ps.: This is my first question here, i'm sorry if I made something wrong. =P

  Read the article

• SQL: select random row from table where the ID of the row isn't in another table?

  - by johnrl

  I've been looking at fast ways to select a random row from a table and have found the following site: http://74.125.77.132/search?q=cache:http://jan.kneschke.de/projects/mysql/order-by-rand/&hl=en&strip=1 What I want to do is to select a random url from my table 'urls' that I DON'T have in my other table 'urlinfo'.The query I am using now selects a random url from 'urls' but I need it modified to only return a random url that is NOT in the 'urlinfo' table. Heres the query: SELECT url FROM urls JOIN (SELECT CEIL(RAND() * (SELECT MAX(urlid) FROM urls ) ) AS urlid ) AS r2 USING(urlid); And the two tables: CREATE TABLE urls ( urlid INT NOT NULL AUTO_INCREMENT PRIMARY KEY, url VARCHAR(255) NOT NULL, ) ENGINE=INNODB; CREATE TABLE urlinfo ( urlid INT NOT NULL PRIMARY KEY, urlinfo VARCHAR(10000), FOREIGN KEY (urlid) REFERENCES urls (urlid) ) ENGINE=INNODB;

  Read the article

• How to pass the structure to a function in C++ defined in another class?

  - by Dany

  I have a class Con as this:- class Con { public: struct MachineList { BSTR AccountId; BSTR MachineId; BSTR Make; char* Make1; BSTR Model; char* Model1; BSTR SerialNumber; BSTR IpAddress; char* IpAddress1; BSTR Port; int Port1; BSTR LocationCode; } machinelist[100] ; int w; } ; i created an object of Con class as Con m_con; I have another class Test class Test { public: void fun();//i want to pass the object of the structure that i created in Con //what arguments should i pass in fun function? };

  Read the article

• Generate fixed length hash in python for url parameter

  - by LeRoy

  I am working in python on appengine. I am trying to create what is equivalent to the "v" value in the youtube url's (http://www.youtube.com/watch?v=XhMN0wlITLk) for retrieving specific entities. The datastore auto generates a key but it is way too long (34 digits). I have experimented with hashlib to build my own, but again I get a long string. I would like to keep it to under 11 digits (I am not dealing with a huge number of entities) and letters and numbers are acceptable. It seems like there should be a pretty standard solution. I am probably just missing it.

  Read the article

• Rails Joins and include columns from joins table

  - by seth.vargo

  I don't understand how to get the columns I want from rails. I have two models - A User and a Profile. A User :has_many Profile (because users can revert back to an earlier version of their profile): > DESCRIBE users; +----------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | username | varchar(255) | NO | UNI | NULL | | | password | varchar(255) | NO | | NULL | | | last_login | datetime | YES | | NULL | | +----------------+--------------+------+-----+---------+----------------+   > DESCRIBE profiles; +----------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | user_id | int(11) | NO | MUL | NULL | | | first_name | varchar(255) | NO | | NULL | | | last_name | varchar(255) | NO | | NULL | | | . . . . . . | | . . . . . . | | . . . . . . | +----------------+--------------+------+-----+---------+----------------+ In SQL, I can run the query: > SELECT * FROM profiles JOIN users ON profiles.user_id = users.id LIMIT 1; +----+-----------+----------+---------------------+---------+---------------+-----+ | id | username | password | last_login | user_id | first_name | ... | +----+-----------+----------+---------------------+---------+---------------+-----+ | 1 | john | ****** | 2010-12-30 18:04:28 | 1 | John | ... | +----+-----------+----------+---------------------+---------+---------------+-----+ See how I get all the columns for BOTH tables JOINED together? However, when I run this same query in Rails, I don't get all the columns I want - I only get those from Profile: # in rails console >> p = Profile.joins(:user).limit(1) >> [#<Profile ...>] >> p.first_name >> NoMethodError: undefined method `first_name' for #<ActiveRecord::Relation:0x102b521d0> from /Library/Ruby/Gems/1.8/gems/activerecord-3.0.1/lib/active_record/relation.rb:373:in `method_missing' from (irb):8 # I do NOT want to do this (AKA I do NOT want to use "includes") >> p.user >> NoMethodError: undefined method `user' for #<ActiveRecord::Relation:0x102b521d0> from /Library/Ruby/Gems/1.8/gems/activerecord-3.0.1/lib/active_record/relation.rb:373:in method_missing' from (irb):9 I want to (efficiently) return an object that has all the properties of Profile and User together. I don't want to :include the user because it doesn't make sense. The user should always be part of the most recent profile as if they were fields within the Profile model. How do I accomplish this?

  Read the article

• Undefined Behavior and Sequence Points Reloaded

  - by Nawaz

  Consider this topic a sequel of the following topic: Previous Installment Undefined Behavior and Sequence Points Let's revisit this funny and convoluted expression (the italicized phrases are taken from the above topic *smile* ): i += ++i; We say this invokes undefined-behavior. I presume that when say this, we implicitly assume that type of i is one of built-in types. So my question is: what if the type of i is a user-defined type? Say it's type is Index which is defined later in this post (see below). Would it still invoke undefined-behavior? If yes, why? Is it not equivalent to writing i.operator+=(i.operator ++()); or even syntactically simpler i.add(i.inc());? Or, do they too invoke undefined-behavior? If no, why not? After all, the object i gets modified twice between consecutive sequence points. Please recall the rule of thumb : an expression can modify an object's value only once between consecutive "sequence points. And if i += ++i is an expression, then it must invoke undefined-behavior. If so, then it's equivalents i.operator+=(i.operator ++()); and i.add(i.inc()); must also invoke undefined-behavior which seems to be untrue! (as far as I understand) Or, i += ++i is not an expression to begin with? If so, then what is it and what is the definition of expression? If it's an expression, and at the same time, it's behavior is also well-defined, then it implies that number of sequence points associated with an expression somehow depends on the type of operands involved in the expression. Am I correct (even partly)? By the way, how about this expression? a[++i] = i; //taken from the previous topic. but here type of `i` is Index. class Index { int state; public: Index(int s) : state(s) {} Index& operator++() { state++; return *this; } Index& operator+=(const Index & index) { state+= index.state; return *this; } operator int() { return state; } Index & add(const Index & index) { state += index.state; return *this; } Index & inc() { state++; return *this; } };

  Read the article

• How does 64 bit code work on OS-X 10.5?

  - by philcolbourn

  I initially thought that 64 bit instructions would not work on OS-X 10.5. I wrote a little test program and compiled it with GCC -m64. I used long long for my 64 bit integers. The assembly instructions used look like they are 64 bit. eg. imultq and movq 8(%rbp),%rax. I seems to work. I am only using printf to display the 64 bit values using %lld. Is this the expected behaviour? Are there any gotcha's that would cause this to fail? Am I allowed to ask multiple questions in a question? Does this work on other OS's?

  Read the article

• What is the proper way to create a recursive entity in the Entity Framework?

  - by Orion Adrian

  I'm currently using VS 2010 RC, and I'm trying to create a model that contains a recursive self-referencing entity. Currently when I import the entity from the model I get an error indicating that the parent property cannot be part of the association because it's set to 'Computed' or 'Identity', though I'm not sure why it does it that way. I've been hand-editing the file to get around that error, but then the model simply doesn't work. What is the proper way to get recursive entities to work in the Entity Framework. CREATE TABLE [dbo].[Appointments]( [AppointmentId] [int] IDENTITY(1,1) NOT NULL, [Description] [nvarchar](1024) NULL, [Start] [datetime] NOT NULL, [End] [datetime] NOT NULL, [Username] [varchar](50) NOT NULL, [RecurrenceRule] [nvarchar](1024) NULL, [RecurrenceState] [varchar](20) NULL, [RecurrenceParentId] [int] NULL, [Annotations] [nvarchar](50) NULL, [Application] [nvarchar](100) NOT NULL, CONSTRAINT [PK_Appointments] PRIMARY KEY CLUSTERED ( [AppointmentId] ASC ) ) GO ALTER TABLE [dbo].[Appointments] WITH CHECK ADD CONSTRAINT [FK_Appointments_ParentAppointments] FOREIGN KEY([RecurrenceParentId]) REFERENCES [dbo].[Appointments] ([AppointmentId]) GO ALTER TABLE [dbo].[Appointments] CHECK CONSTRAINT [FK_Appointments_ParentAppointments] GO

  Read the article

• How to format a function pointer?

  - by Longpoke

  Is there any way to print a pointer to a function in ANSI C? Of course this means you have to cast the function pointer to void pointer, but it appears that's not possible?? #include <stdio.h> int main() { int (*funcptr)() = main; printf("%p\n", (void* )funcptr); printf("%p\n", (void* )main); return 0; } $ gcc -ansi -pedantic -Wall test.c -o test test.c: In function 'main': test.c:6: warning: ISO C forbids conversion of function pointer to object pointer type test.c:7: warning: ISO C forbids conversion of function pointer to object pointer type $ ./test 0x400518 0x400518 It's "working", but non-standard...

  Read the article

• Error while excuting a simple boost thread program

  - by Eternal Learner

  Hi All, Could you tell mw what is the problem with the below boost::thread program #include<iostream> #include<boost/thread/thread.hpp> boost::mutex mutex; class A { public: A() : a(0) {} void operator()() { boost::mutex::scoped_lock lock(mutex); } private: int a; }; int main() { boost::thread thr1(A()); boost::thread thr2(A()); thr1.join(); thr2.join(); } I get the error message: error: request for member 'join' in 'thr1', which is of non-class type 'boost::thread()(A ()())' BoostThread2.cpp:30: error: request for member 'join' in 'thr2', which is of non-class type 'boost::thread ()(A ()())'

  Read the article

• function parameter used to store value

  - by user248247

  Hi, I have to define an interface. The API in my homework is stated below: int generate_codes(char * ssn, char * student_id); int denotes 0 or 1 for pass or fail. studentid is an output param should return a 6 digit id. ssn is a 9 digit input param they school program will take ssn's and use my code to generate the student id. now from an API perspective should I not be using const char * for both parameters. should the studentid not be passed in by reference? rather than by pointer? can someone tell me how i can easily use the pointer in my test app which uses my api to get the pointer such that it prints a std::string from a char *? my app code looks something like const char * ssn = "987098765" const char * studnt_id = new char [7]; int value = -1; value = generate_codes(ssn,studnt_id); std::string test(studnt_id); std::cout<<"student id= "<<test<<" Pass/fail= "<<value<<std::endl; delete [] studnt_id; return 0; I basically got an error about << not being compatible with the right hand side of the operand. When i changed the code to std::cout<<"student id= "<<test.c_str()<<" Pass/fail= "<<value<<std::endl; then it worked but i get garbage for the value. not sure how to do get the value form the pointer. THe value inside the function prints just fine. but when i try to print it outside of the function it prints garbage. Inside the above function I do set the studndt_id like so std::string str_studnt_id = studnt_id; should that make the address of the str_studnt point to the address of studnt_id and thus any changes I make to the value that its pointing to it should reflect outside the function?

  Read the article

• GDB hardware watchpoint very slow - why?

  - by Laurynas Biveinis

  On a large C application, I have set a hardware watchpoint on a memory address as follows: (gdb) watch *((int*)0x12F5D58) Hardware watchpoint 3: *((int*)0x12F5D58) As you can see, it's a hardware watchpoint, not software, which would explain the slowness. Now the application running time under debugger has changed from less than ten seconds to one hour and counting. The watchpoint has triggered three times so far, the first time after 15 minutes when the memory page containing the address was made readable by sbrk. Surely during those 15 minutes the watchpoint should have been efficient since the memory page was inaccessible? And that still does not explain, why it's so slow afterwards. The GDB is $ gdb --version GNU gdb (GDB) 7.0-ubuntu [...] Thanks in advance for any ideas as what might be the cause or how to fix/work around it.

  Read the article

• Java NumberFormatException

  - by Bragaadeesh

  Hi, I am trying to do a conversion of a String to integer for which I get a NumberFormatException. The reason is pretty obvious. But I need a workaround here. Following is the sample code. public class NumberFormatTest { public static void main(String[] args) { String num = "9.18E+09"; try{ long val = Long.valueOf(num); }catch(NumberFormatException ne){ //Try to convert the value to 9180000000 here } } } I need the logic that goes in the comment section, a generic one would be nice. Thanks.

  Read the article

• "is not abstact and does not override abstract method."

  - by Chris Bolton

  So I'm pretty new to android development and have been trying to piece together some code bits. Here's what I have so far: package com.teslaprime.prirt; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.ListView; import android.widget.AdapterView.OnItemClickListener; import java.util.ArrayList; import java.util.List; public class TaskList extends Activity { List<Task> model = new ArrayList<Task>(); ArrayAdapter<Task> adapter = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button add = (Button) findViewById(R.id.add); add.setOnClickListener(onAdd); ListView list = (ListView) findViewById(R.id.tasks); adapter = new ArrayAdapter<Task>(this,android.R.layout.simple_list_item_1,model); list.setAdapter(adapter); list.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(View v, int position, long id) { adapter.remove(position); } });} private View.OnClickListener onAdd = new View.OnClickListener() { public void onClick(View v) { Task task = new Task(); EditText name = (EditText) findViewById(R.id.taskEntry); task.name = name.getText().toString(); adapter.add(task); } }; } and here are the errors I'm getting: compile: [javac] /opt/android-sdk/tools/ant/main_rules.xml:384: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds [javac] Compiling 2 source files to /home/chris-kun/code/priRT/bin/classes [javac] /home/chris-kun/code/priRT/src/com/teslaprime/prirt/TaskList.java:30: <anonymous com.teslaprime.prirt.TaskList$1> is not abstract and does not override abstract method onItemClick(android.widget.AdapterView<?>,android.view.View,int,long) in android.widget.AdapterView.OnItemClickListener [javac] list.setOnItemClickListener(new OnItemClickListener() { [javac] ^ [javac] /home/chris-kun/code/priRT/src/com/teslaprime/prirt/TaskList.java:32: remove(com.teslaprime.prirt.Task) in android.widget.ArrayAdapter<com.teslaprime.prirt.Task> cannot be applied to (int) [javac] adapter.remove(position); [javac] ^ [javac] 2 errors BUILD FAILED /opt/android-sdk/tools/ant/main_rules.xml:384: Compile failed; see the compiler error output for details. Total time: 2 seconds any ideas?

  Read the article

< Previous Page | 484 485 486 487 488 489 490 491 492 493 494 495  | Next Page >