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  • Delete array of size 1

    - by Arne
    This is possibly a candidate for a one-line answer. I would like know it anyway.. I am writing a simple circular buffer and for some reasons that are not important for the question I need to implement it using an array of doubles. In fact I have not investiated other ways to do it, but since an array is required anyway I have not spent much time on looking for alternatives. template<typename T> class CircularBuffer { public: CircularBuffer(unsigned int size); ~CircularBuffer(); void Resize(unsigned int new_size); ... private: T* buffer; unsigned int buffer_size; }; Since I need to have the buffer dynamically sized the buffer_size is neither const nor a template parameter. Now the question: During construction and in function Resize(int) I only require the size to be at least one, although a buffer of size one is effectively no longer a buffer. Of course using a simple double instead would be more appropriate but anyway. Now when deleting the internal buffer in the destructor - or in function resize for that matter - I need to delete the allocated memory. Question is, how? First candidate is of course delete[] buffer; but then again, if I have allocated a buffer of size one, that is if the pointer was aquired with buffer = new T[0], is it still appropriate to call delete[] on the pointer or do I need to call delete buffer; (without brackets) ? Thanks, Arne

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  • Cocoa NSStream TCP connection to FTP

    - by Chuck
    Hi, I'm new to Cocoa, but not to programming. Recently I decided I wanted to write a FTP client for Mac, and so I first made it in the language I'm most comfortable in (on Windows), and then moved on to Cocoa when I had the workings of FTP communications down. My question is (apparently) a bit controversial: How do I establish a read/writeable connection to (a ftp server)? What I have so far (non working obviously): NSInputStream *iStream; NSOutputStream *oStream; NSHost *host = [NSHost hostWithAddress:@"127.0.0.1"]; [NSStream getStreamsToHost:host port:3333 inputStream:&iStream outputStream:&oStream]; // ftp port: 3333 [iStream retain]; [oStream retain]; [iStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [oStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [iStream setDelegate:self]; [oStream setDelegate:self]; // which is not implemented apparently [iStream open]; [oStream open]; // .... [iStream write: (const uint8_t *)buf maxLength:8]; Which is partially based on http://developer.apple.com/mac/library/documentation/cocoa/Conceptual/Streams/Articles/NetworkStreams.html Now, why have I chosen NSStream? Because while this question is merely about how to connect to a FTP stream, my whole project will also include SSL and as far as I've been able to search here and on google, NSStream is capable of "switching" to a SSL connection. I've not been able to see the connection being made (which I'm usually able to do), but I also heard something about having to write to the stream before the stream will open? Any pointers are greatly appreciated, and sorry if my question is annoying - I'm new to Cocoa :)

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  • How can I use Qt to get html code of the redirected page??

    - by Claire Huang
    I'm trying to use Qt to download the html code from the following url: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=nucleotide&cmd=search&term=AB100362 this url will re-direct to www.ncbi.nlm.nih.gov/nuccore/27884304 I try to do it by following way, but I cannot get anything. it works for some webpage such as www.google.com, but not for this NCBI page. is there any way to get this page?? QNetworkReply::NetworkError downloadURL(const QUrl &url, QByteArray &data) { QNetworkAccessManager manager; QNetworkRequest request(url); QNetworkReply *reply = manager.get(request); QEventLoop loop; QObject::connect(reply, SIGNAL(finished()), &loop, SLOT(quit())); loop.exec(); if (reply->error() != QNetworkReply::NoError) { return reply->error(); } data = reply->readAll(); delete reply; return QNetworkReply::NoError; } void GetGi() { int pos; QString sGetFromURL = "http://www.ncbi.nlm.nih.gov/entrez/query.fcgi"; QUrl url(sGetFromURL); url.addQueryItem("db", "nucleotide"); url.addQueryItem("cmd", "search"); url.addQueryItem("term", "AB100362"); QByteArray InfoNCBI; int errorCode = downloadURL(url, InfoNCBI); if (errorCode != 0 ) { QMessageBox::about(0,tr("Internet Error "), tr("Internet Error %1: Failed to connect to NCBI.\t\nPlease check your internect connection.").arg(errorCode)); return "ERROR"; } }

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  • Render User Controls and call their Page_Load

    - by David Murdoch
    The following code will not work because the controls (page1, page2, page3) require that their "Page_Load" event gets called. using System; using System.IO; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using iTextSharp.text; using iTextSharp.text.html.simpleparser; using iTextSharp.text.pdf; public partial class utilities_getPDF : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { // add user controls to the page AddContentControl("controls/page1"); AddContentControl("controls/page2"); AddContentControl("controls/page3"); // set up the response to download the rendered PDF... Response.ContentType = "application/pdf"; Response.ContentEncoding = System.Text.Encoding.UTF8; Response.AddHeader("Content-Disposition", "attachment;filename=FileName.pdf"); Response.Cache.SetCacheability(HttpCacheability.NoCache); // get the rendered HTML of the page System.IO.StringWriter stringWrite = new StringWriter(); System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite); this.Render(htmlWrite); StringReader reader = new StringReader(stringWrite.ToString()); // write the PDF to the OutputStream... Document doc = new Document(PageSize.A4); HTMLWorker parser = new HTMLWorker(doc); PdfWriter.GetInstance(doc, Response.OutputStream); doc.Open(); parser.Parse(reader); doc.Close(); } // the parts are probably irrelevant to the question... private const string contentPage = "~/includes/{0}.ascx"; private void AddContentControl(string page) { content.Controls.Add(myLoadControl(page)); } private Control myLoadControl(string page) { return TemplateControl.LoadControl(string.Format(contentPage, page)); } } So my question is: How can I get the controls HTML?

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  • Global Hotkey in Mono and Gtk#

    - by Zach Johnson
    I'm trying to get a global hotkey working in Linux using Mono. I found the signatures of XGrabKey and XUngrabKey, but I can't seem to get them working. Whenever I try to invoke XGrabKey, the application crashes with a SIGSEGV. This is what I have so far: using System; using Gtk; using System.Runtime.InteropServices; namespace GTKTest { class MainClass { const int GrabModeAsync = 1; public static void Main(string[] args) { Application.Init(); MainWindow win = new MainWindow(); win.Show(); // Crashes here XGrabKey( win.Display.Handle, (int)Gdk.Key.A, (uint)KeyMasks.ShiftMask, win.Handle, true, GrabModeAsync, GrabModeAsync); Application.Run(); XUngrabKey( win.Display.Handle, (int)Gdk.Key.A, (uint)KeyMasks.ShiftMask, win.Handle); } [DllImport("libX11")] internal static extern int XGrabKey( IntPtr display, int keycode, uint modifiers, IntPtr grab_window, bool owner_events, int pointer_mode, int keyboard_mode); [DllImport("libX11")] internal static extern int XUngrabKey( IntPtr display, int keycode, uint modifiers, IntPtr grab_window); } public enum KeyMasks { ShiftMask = (1 << 0), LockMask = (1 << 1), ControlMask = (1 << 2), Mod1Mask = (1 << 3), Mod2Mask = (1 << 4), Mod3Mask = (1 << 5), Mod4Mask = (1 << 6), Mod5Mask = (1 << 7) } } Does anyone have a working example of XGrabKey? Thanks!

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  • sqlite3 update text in uitextview

    - by summer
    i had the sqlite statement ready for update..but i am confuse about grabbing text from uitextview and updating it..and i waned to update it using a uibutton..how do i carry on after creating the sql statement???kinda lost..any new solution is appreciate.. - (void) saveAllData { if(isDirty) { if(updateStmt == nil) { const char *sql = "update Snap Set snapTitle = ?, snapDesc = ?, Where snapID = ?"; if(sqlite3_prepare_v2(database, sql, -1, &updateStmt, NULL) != SQLITE_OK) NSAssert1(0, @"Error while creating update statement. '%s'", sqlite3_errmsg(database)); } sqlite3_bind_text(updateStmt, 1, [snapTitle UTF8String], -1, SQLITE_TRANSIENT); sqlite3_bind_text(updateStmt, 2, [snapDescription UTF8String], -2, SQLITE_TRANSIENT); sqlite3_bind_int(updateStmt, 3, snapID); if(SQLITE_DONE != sqlite3_step(updateStmt)) NSAssert1(0, @"Error while updating. '%s'", sqlite3_errmsg(database)); sqlite3_reset(updateStmt); isDirty = NO; } //Reclaim all memory here. [snapTitle release]; snapTitle = nil; [snapDescription release]; snapDescription = nil; //isDetailViewHydrated = NO; }

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  • How to implement a counter when using golang's goroutine?

    - by MrROY
    I'm trying to make a queue struct that have push and pop functions. I need to use 10 threads push and another 10 threads pop data, just like i did in the code below. Questions : 1. I need to print out how much i have pushed/popped, but i don't know how to do that. 2. Is there anyway to speed up my code ? the code is too slow for me. package main import ( "runtime" "time" ) const ( DATA_SIZE_PER_THREAD = 10000000 ) type Queue struct { records string } func (self Queue) push(record chan interface{}) { // need push counter record <- time.Now() } func (self Queue) pop(record chan interface{}) { // need pop counter <- record } func main() { runtime.GOMAXPROCS(runtime.NumCPU()) //record chan record := make(chan interface{},1000000) //finish flag chan finish := make(chan bool) queue := new(Queue) for i:=0; i<10; i++ { go func() { for j:=0; j<DATA_SIZE_PER_THREAD; j++ { queue.push(record) } finish<-true }() } for i:=0; i<10; i++ { go func() { for j:=0; j<DATA_SIZE_PER_THREAD; j++ { queue.pop(record) } finish<-true }() } for i:=0; i<20; i++ { <-finish } }

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  • Extracting bool from istream in a templated function

    - by Thomas Matthews
    I'm converting my fields class read functions into one template function. I have field classes for int, unsigned int, long, and unsigned long. These all use the same method for extracting a value from an istringstream (only the types change): template <typename Value_Type> Value_Type Extract_Value(const std::string& input_string) { std::istringstream m_string_stream; m_string_stream.str(input_string); m_string_stream.clear(); m_string_stream >> value; return; } The tricky part is with the bool (Boolean) type. There are many textual representations for Boolean: 0, 1, T, F, TRUE, FALSE, and all the case insensitive combinations Here's the questions: What does the C++ standard say are valid data to extract a bool, using the stream extraction operator? Since Boolean can be represented by text, does this involve locales? Is this platform dependent? I would like to simplify my code by not writing my own handler for bool input. I am using MS Visual Studio 2008 (version 9), C++, and Windows XP and Vista.

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  • optimizing an sql query using inner join and order by

    - by Sergio B
    I'm trying to optimize the following query without success. Any idea where it could be indexed to prevent the temporary table and the filesort? EXPLAIN SELECT SQL_NO_CACHE `groups`.* FROM `groups` INNER JOIN `memberships` ON `groups`.id = `memberships`.group_id WHERE ((`memberships`.user_id = 1) AND (`memberships`.`status_code` = 1 AND `memberships`.`manager` = 0)) ORDER BY groups.created_at DESC LIMIT 5;` +----+-------------+-------------+--------+--------------------------+---------+---------+---------------------------------------------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------------+--------+--------------------------+---------+---------+---------------------------------------------+------+----------------------------------------------+ | 1 | SIMPLE | memberships | ref | grp_usr,grp,usr,grp_mngr | usr | 5 | const | 5 | Using where; Using temporary; Using filesort | | 1 | SIMPLE | groups | eq_ref | PRIMARY | PRIMARY | 4 | sportspool_development.memberships.group_id | 1 | | +----+-------------+-------------+--------+--------------------------+---------+---------+---------------------------------------------+------+----------------------------------------------+ 2 rows in set (0.00 sec) +--------+------------+-----------------------------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +--------+------------+-----------------------------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+ | groups | 0 | PRIMARY | 1 | id | A | 6 | NULL | NULL | | BTREE | | | groups | 1 | index_groups_on_name | 1 | name | A | 6 | NULL | NULL | YES | BTREE | | | groups | 1 | index_groups_on_privacy_setting | 1 | privacy_setting | A | 6 | NULL | NULL | YES | BTREE | | | groups | 1 | index_groups_on_created_at | 1 | created_at | A | 6 | NULL | NULL | YES | BTREE | | | groups | 1 | index_groups_on_id_and_created_at | 1 | id | A | 6 | NULL | NULL | | BTREE | | | groups | 1 | index_groups_on_id_and_created_at | 2 | created_at | A | 6 | NULL | NULL | YES | BTREE | | +--------+------------+-----------------------------------+--------------+-----------------+-----------+-------------+----------+--------+------+------------+---------+ +-------------+------------+----------------------------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +-------------+------------+----------------------------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+ | memberships | 0 | PRIMARY | 1 | id | A | 2 | NULL | NULL | | BTREE | | | memberships | 0 | grp_usr | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 0 | grp_usr | 2 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | grp | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | usr | 1 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | grp_mngr | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | grp_mngr | 2 | manager | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 1 | group_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 2 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 3 | status_code | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | complex_index | 4 | manager | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | index_memberships_on_user_id_and_status_code_and_manager | 1 | user_id | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | index_memberships_on_user_id_and_status_code_and_manager | 2 | status_code | A | 2 | NULL | NULL | YES | BTREE | | | memberships | 1 | index_memberships_on_user_id_and_status_code_and_manager | 3 | manager | A | 2 | NULL | NULL | YES | BTREE | | +-------------+------------+----------------------------------------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+

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  • Unknown Exception on trying to initialize the web service stub created by Axis C++

    - by Harsha Reddy
    Hi, I am trying out the sample calculator program given in the folder of axis c++. I am mainly interested in the client side. So I used the wsdl to create the stubs and my main is pretty much the same as given in the sample. However on executing the call Calculator ws (endpoint) I get an unknown exception "First-chance exception at 0x7c0024b9 in CalculatorClient.exe: 0xC0000005: Access violation reading location 0x00000000. First-chance exception at 0x7c812afb in CalculatorClient.exe: Microsoft C++ exception: [rethrow] at memory location 0x00000000.. Unhandled exception at 0x7c0024b9 in CalculatorClient.exe: 0xC0000005: Access violation reading location 0x00000000." and the exception causing code is Calculator::Calculator(const char* pchEndpointUri, AXIS_PROTOCOL_TYPE eProtocol) :Stub(pchEndpointUri, eProtocol) { } I had earlier tried to run a a webservice using Axis C++ but had received the same error. At that time my web service was a java ws on WAS. Then I later tried the calculator client (but this time I did not have any server hosting the ws as I just wanted to check if the Client could initialize). Is the problem caused due to the web service not being hosted on Apache in C++ (though I highly doubt it). Any help would be appreciated. Thanks, Harsha

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  • Calling unmanaged dll from C#. Take 2

    - by Charles Gargent
    I have written a c# program that calls a c++ dll that echoes the commandline args to a file When the c++ is called using the rundll32 command it displays the commandline args no problem, however when it is called from within the c# it doesnt. I asked this question to try and solve my problem, but I have modified it my test environment and I think it is worth asking a new question. Here is the c++ dll #include "stdafx.h" #include "stdlib.h" #include <stdio.h> #include <iostream> #include <fstream> using namespace std; BOOL APIENTRY DllMain( HANDLE hModule, DWORD ul_reason_for_call, LPVOID lpReserved ) { return TRUE; } extern "C" __declspec(dllexport) int WINAPI CMAKEX( HWND hwnd, HINSTANCE hinst, LPCSTR lpszCommandLine, DWORD dwReserved) { ofstream SaveFile("output.txt"); SaveFile << lpszCommandLine; SaveFile.close(); return 0; } Here is the c# app using System; using System.Collections.Generic; using System.Text; using System.Security.Cryptography; using System.Runtime.InteropServices; using System.Net; namespace nac { class Program { [DllImport("cmakca.dll", SetLastError = true, CharSet = CharSet.Unicode)] static extern bool CMAKEX(IntPtr hwnd, IntPtr hinst, string lpszCmdLine, int nCmdShow); static void Main(string[] args) { string cmdLine = @"/source_filename proxy-1.txt /backup_filename proxy.bak /DialRasEntry NULL /TunnelRasEntry DSLVPN /profile ""C:\Documents and Settings\Administrator\Application Data\Microsoft\Network\Connections\Cm\dslvpn.cmp"""; const int SW_SHOWNORMAL = 1; CMAKEX(IntPtr.Zero, IntPtr.Zero, cmdLine, SW_SHOWNORMAL).ToString(); } } } The output from the rundll32 command is rundll32 cmakex.dll,CMAKEX /source_filename proxy-1.txt /backup_filename proxy.bak /DialRasEntry NULL /TunnelRasEntry DSLVPN /profile ""C:\Documents and Settings\Administrator\Application Data\Microsoft\Network\Connections\Cm\dslvpn.cmp" /source_filename proxy-1.txt /backup_filename proxy.bak /DialRasEntry NULL /TunnelRasEntry DSLVPN /profile ""C:\Documents and Settings\Administrator\Application Data\Microsoft\Network\Connections\Cm\dslvpn.cmp" however the output when the c# app runs is /

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  • Visual C++ Testing problem

    - by JamesMCCullum
    Hi there I have installed VisualAssert and cFix. I have been using Visual Studio C++ and programming in CLI/C++. I have a working Chess Game Program that works perfectly by itself.....and I have been studying testing and have many examples(with tutorials) I have found on the net, that compile and run in Visual Studio..... But as soon as I try and implement those tests on my chess game......I get this problem.... This is what its telling me 1>------ Build started: Project: ChessRound1, Configuration: Debug Win32 ------ 1>Compiling... 1>stdafx.cpp 1>C:\Program Files\VisualAssert\include\cfixpe.h(137) : error C3641: 'CfixpCrtInitEmbedding' : invalid calling convention '__cdecl ' for function compiled with /clr:pure or /clr:safe 1>C:\Program Files\VisualAssert\include\cfixpe.h(235) : error C4394: 'CfixpCrtInitEmbeddingRegistration' : per-appdomain symbol should not be marked with __declspec(allocate) 1>C:\Program Files\VisualAssert\include\cfixpe.h(235) : error C2393: 'CfixpCrtInitEmbeddingRegistration' : per-appdomain symbol cannot be allocated in segment '.CRT$XCX' 1>C:\Program Files\VisualAssert\include\cfixpe.h(244) : error C2440: 'initializing' : cannot convert from 'void (__cdecl *)(void)' to 'const CFIX_CRT_INIT_ROUTINE' 1> Address of a function yields __clrcall calling convention in /clr:pure and /clr:safe; consider using __clrcall in target type 1>C:\Program Files\VisualAssert\include\cfixpe.h(137) : error C3641: 'CfixpCrtInitEmbedding' : invalid calling convention '__cdecl ' for function compiled with /clr:pure or /clr:safe 1>Build log was saved at "file://c:\Users\james\Documents\Visual Studio 2008\Projects\ChessRound1\ChessRound1\Debug\BuildLog.htm" 1>ChessRound1 - 4 error(s), 0 warning(s) ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Any ideas what I'm doing wrong? Im working with windows forms and have a heap of cpp source files. Any help would be appreciated. Thanks

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  • Delphi - Is there a better way to get state abbreviations from state names

    - by Bill
    const states : array [0..49,0..1] of string = ( ('Alabama','AL'), ('Montana','MT'), ('Alaska','AK'), ('Nebraska','NE'), ('Arizona','AZ'), ('Nevada','NV'), ('Arkansas','AR'), ('New Hampshire','NH'), ('California','CA'), ('New Jersey','NJ'), ('Colorado','CO'), ('New Mexico','NM'), ('Connecticut','CT'), ('New York','NY'), ('Delaware','DE'), ('North Carolina','NC'), ('Florida','FL'), ('North Dakota','ND'), ('Georgia','GA'), ('Ohio','OH'), ('Hawaii','HI'), ('Oklahoma','OK'), ('Idaho','ID'), ('Oregon','OR'), ('Illinois','IL'), ('Pennsylvania','PA'), ('Indiana','IN'), ('Rhode Island','RI'), ('Iowa','IA'), ('South Carolin','SC'), ('Kansas','KS'), ('South Dakota','SD'), ('Kentucky','KY'), ('Tennessee','TN'), ('Louisiana','LA'), ('Texas','TX'), ('Maine','ME'), ('Utah','UT'), ('Maryland','MD'), ('Vermont','VT'), ('Massachusetts','MA'), ('Virginia','VA'), ('Michigan','MI'), ('Washington','WA'), ('Minnesota','MN'), ('West Virginia','WV'), ('Mississippi','MS'), ('Wisconsin','WI'), ('Missouri','MO'), ('Wyoming','WY') ); function getabb(state:string):string; var I:integer; begin for I := 0 to length(states) -1 do if lowercase(state) = lowercase(states[I,0]) then begin result:= states[I,1]; end; end; function getstate(state:string):string; var I:integer; begin for I := 0 to length(states) -1 do if lowercase(state) = lowercase(states[I,1]) then begin result:= states[I,0]; end; end; procedure TForm2.Button1Click(Sender: TObject); begin edit1.Text:=getabb(edit1.Text); end; procedure TForm2.Button2Click(Sender: TObject); begin edit1.Text:=getstate(edit1.Text); end; end. Is there a bette way to do this?

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  • C# using consts in static classes

    - by NickLarsen
    I was plugging away on an open source project this past weekend when I ran into a bit of code that confused me to look up the usage in the C# specification. The code in questions is as follows: internal static class SomeStaticClass { private const int CommonlyUsedValue = 42; internal static string UseCommonlyUsedValue(...) { // some code value = CommonlyUsedValue + ...; return value.ToString(); } } I was caught off guard because this appears to be a non static field being used by a static function which some how compiled just fine in a static class! The specification states (§10.4): A constant-declaration may include a set of attributes (§17), a new modifier (§10.3.4), and a valid combination of the four access modifiers (§10.3.5). The attributes and modifiers apply to all of the members declared by the constant-declaration. Even though constants are considered static members, a constant-declaration neither requires nor allows a static modifier. It is an error for the same modifier to appear multiple times in a constant declaration. So now it makes a little more sense because constants are considered static members, but the rest of the sentence is a bit surprising to me. Why is it that a constant-declaration neither requires nor allows a static modifier? Admittedly I did not know the spec well enough for this to immediately make sense in the first place, but why was the decision made to not force constants to use the static modifier if they are considered constants? Looking at the last sentence in that paragraph, I cannot figure out if it is regarding the previous statement directly and there is some implicit static modifier on constants to begin with, or if it stands on its own as another rule for constants. Can anyone help me clear this up?

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  • Bad linking in Qt unit test -- missing the link to the moc file?

    - by dwj
    I'm trying to unit test a class that inherits QObject; the class itself is located up one level in my directory structure. When I build the unit test I get the standard unresolved errors if a class' MOC file cannot be found: test.obj : error LNK2001: unresolved external symbol "public: virtual void * __thiscall UnitToTest::qt_metacast(char const *)" (?qt_metacast@UnitToTest@@UAEPAXPBD@Z) + 2 missing functions The MOC file is created but appears to not be linking. I've been poking around SO, the web, and Qt's docs for quite a while and have hit a wall. How do I get the unit test to include the MOC file in the link? ==== My project file is dead simple: TEMPLATE = app TARGET = test DESTDIR = . CONFIG += qtestlib INCLUDEPATH += . .. DEPENDPATH += . HEADERS += test.h SOURCES += test.cpp ../UnitToTest.cpp stubs.cpp DEFINES += UNIT_TEST My directory structure and files: C:. | UnitToTest.cpp | UnitToTest.h | \---test | test.cpp (Makefiles removed for clarity) | test.h | test.pro | stubs.cpp | +---debug | UnitToTest.obj | test.obj | test.pdb | moc_test.cpp | moc_test.obj | stubs.obj Edit: Additional information The generated Makefile.Debug shows the moc file missing: SOURCES = test.cpp \ ..\test.cpp \ stubs.cpp debug\moc_test.cpp OBJECTS = debug\test.obj \ debug\UnitToTest.obj \ debug\stubs.obj \ debug\moc_test.obj

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  • How to parse kanji numeric characters using ICU?

    - by Aki
    I'm writing a function using ICU to parse an Unicode string which consists of kanji numeric character(s) and want to return the integer value of the string. "?" = 5 "???" = 31 "???????" = 5972 I'm setting the locale to Locale::getJapan() and using the NumberFormat::parse() to parse the character string. However, whenever I pass it any Kanji characters, the parse() method is returning U_INVALID_FORMAT_ERROR. Does anyone know if ICU supports Kanji character strings in the NumberFormat::parse() method? I was hoping that since I'm setting the Locale to Japanese that it would be able to parse Kanji numeric values. Thanks! #include <iostream> #include <unicode/numfmt.h> using namespace std; int main(int argc, char **argv) { const Locale &jaLocale = Locale::getJapan(); UErrorCode status = U_ZERO_ERROR; NumberFormat *nf = NumberFormat::createInstance(jaLocale, status); UChar number[] = {0x4E94}; // Character for '5' in Japanese '?' UnicodeString numStr(number); Formattable formattable; nf->parse(numStr, formattable, status); if (U_FAILURE(status)) { cout << "error parsing as number: " << u_errorName(status) << endl; return(1); } cout << "long value: " << formattable.getLong() << endl; }

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  • operator<< overload,

    - by mr.low
    //using namespace std; using std::ifstream; using std::ofstream; using std::cout; class Dog { friend ostream& operator<< (ostream&, const Dog&); public: char* name; char* breed; char* gender; Dog(); ~Dog(); }; im trying to overload the << operator. I'm also trying to practice good coding. But my code wont compile unless i uncomment the using namespace std. i keep getting this error and i dont know. im using g++ compiler. Dog.h:20: error: ISO C++ forbids declaration of ‘ostream’ with no type Dog.h:20: error: ‘ostream’ is neither function nor member function; cannot be declared friend. if i add line using std::cout; then i get this error. Dog.h:21: error: ISO C++ forbids declaration of ‘ostream’ with no type. Can somebody tell me the correct way to overload the << operator with out using namespace std;

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  • Compiler optimization causing the performance to slow down

    - by aJ
    I have one strange problem. I have following piece of code: template<clss index, class policy> inline int CBase<index,policy>::func(const A& test_in, int* srcPtr ,int* dstPtr) { int width = test_in.width(); int height = test_in.height(); double d = 0.0; //here is the problem for(int y = 0; y < height; y++) { //Pointer initializations //multiplication involving y //ex: int z = someBigNumber*y + someOtherBigNumber; for(int x = 0; x < width; x++) { //multiplication involving x //ex: int z = someBigNumber*x + someOtherBigNumber; if(soemCondition) { // floating point calculations } *dstPtr++ = array[*srcPtr++]; } } } The inner loop gets executed nearly 200,000 times and the entire function takes 100 ms for completion. ( profiled using AQTimer) I found an unused variable double d = 0.0; outside the outer loop and removed the same. After this change, suddenly the method is taking 500ms for the same number of executions. ( 5 times slower). This behavior is reproducible in different machines with different processor types. (Core2, dualcore processors). I am using VC6 compiler with optimization level O2. Follwing are the other compiler options used : -MD -O2 -Z7 -GR -GX -G5 -X -GF -EHa I suspected compiler optimizations and removed the compiler optimization /O2. After that function became normal and it is taking 100ms as old code. Could anyone throw some light on this strange behavior? Why compiler optimization should slow down performance when I remove unused variable ? Note: The assembly code (before and after the change) looked same.

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  • Use of for_each on map elements

    - by Antonio
    I have a map where I'd like to perform a call on every data type object member function. I yet know how to do this on any sequence but, is it possible to do it on an associative container? The closest answer I could find was this: Boost.Bind to access std::map elements in std::for_each. But I cannot use boost in my project so, is there an STL alternative that I'm missing to boost::bind? If not possible, I thought on creating a temporary sequence for pointers to the data objects and then, call for_each on it, something like this: class MyClass { public: void Method() const; } std::map<int, MyClass> Map; //... std::vector<MyClass*> Vector; std::transform(Map.begin(), Map.end(), std::back_inserter(Vector), std::mem_fun_ref(&std::map<int, MyClass>::value_type::second)); std::for_each(Vector.begin(), Vector.end(), std::mem_fun(&MyClass::Method)); It looks too obfuscated and I don't really like it. Any suggestions?

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  • How do I pass a callback function to sqlite3_exec on iOS 5.1?

    - by John Doh
    I am new to both xcode/iOS/Objective-C and sqlite. I am trying to teach myself the basics - and I would like to use the sqlite3 wrapper "sqlite3_exec" for a select query. For some reason, I can't find a simple example anywhere of someone doing this. Basically, the method has a parameter (the third one) for a callback function: int sqlite3_exec( sqlite3*, /* An open database */ const char *sql, /* SQL to be evaluated */ int (*callback)(void*,int,char**,char**), /* Callback function */ void *, /* 1st argument to callback */ char **errmsg /* Error msg written here */ ); That's fine. I'm no stranger to callbacks. However, I just can't seem to get the syntax down right. I took over one of the view controllers in my iPad (iOS 5.1) xcode (4.3) project, and made the changes shown below: #import "SecondViewController.h" #import "sqlite3.h" #import "AppState.h" @interface SecondViewController () @end @implementation SecondViewController - (int)myCallback:(void *)a_parm argc:(int)argc argv:(char **)argv column:(char **)column { return 0; } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. //grab questionnaire names char *sql = "select * from QST2Main order by [Name]"; char *err = nil; sqlite3 *db = [[AppState sharedManager] getgCn]; sqlite3_exec(db, sql, myCallback, nil, &err); } Essentially, I want to run a query when this view first loads, to store some data for later use. But, XCode doesn't like the "myCallback" usage at the bottom there. It says: Undeclared Use of Identifier 'myCallback.' That method is declared in the header file, and I've even tried making it static. Nothing seems to make this error go away. I know I must be doing something fundamentally wrong here, but for the life of me I can't figure out what - I can't even find other code samples in this area that could help me figure out what I'm missing. Many thanks!

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  • Encode and Decode using UTF-8 in iphone

    - by Ekra
    Hi friends, I wanted an example were in I can encode and then decode the same string using UTF-8. Encode and then Decode means I want to implement the method in 2 area were one can encode it and other is able to decode it. I have seen the API but I didnt get much success:- StringWithCString:encoding: stringWithUTF8String: stringWithCString:(const char *)cString encoding:(NSStringEncoding)enc; =================EDITED================= I have string as "øæ-test-2.txt" . when I am encoding it char *s = "øæ-test-2.txt"; NSString *enc = [NSString stringWithCString:s encoding:NSASCIIStringEncoding]; I am getting "øæ-test-2.txt" as output. Now I want to get back the original string back i.e. "øæ-test-2.txt" +++++++++EDITED+++++++++++++++++++ I am getting "øæ-test-2.txt" from server and I need "øæ-test-2.txt" by decoding it . I am able to get the output from the link below http://www.cafewebmaster.com/online_tools/utf_decode Please try to use the link and u will understand my concern. I need the solution on urgent basis. It would be highly appreciated if anyone can give some hint or tutorial in right direction. Regards

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  • Instantiating class with custom allocator in shared memory

    - by recipriversexclusion
    I'm pulling my hair due to the following problem: I am following the example given in boost.interprocess documentation to instantiate a fixed-size ring buffer buffer class that I wrote in shared memory. The skeleton constructor for my class is: template<typename ItemType, class Allocator > SharedMemoryBuffer<ItemType, Allocator>::SharedMemoryBuffer( unsigned long capacity ){ m_capacity = capacity; // Create the buffer nodes. m_start_ptr = this->allocator->allocate(); // allocate first buffer node BufferNode* ptr = m_start_ptr; for( int i = 0 ; i < this->capacity()-1; i++ ) { BufferNode* p = this->allocator->allocate(); // allocate a buffer node } } My first question: Does this sort of allocation guarantee that the buffer nodes are allocated in contiguous memory locations, i.e. when I try to access the n'th node from address m_start_ptr + n*sizeof(BufferNode) in my Read() method would it work? If not, what's a better way to keep the nodes, creating a linked list? My test harness is the following: // Define an STL compatible allocator of ints that allocates from the managed_shared_memory. // This allocator will allow placing containers in the segment typedef allocator<int, managed_shared_memory::segment_manager> ShmemAllocator; //Alias a vector that uses the previous STL-like allocator so that allocates //its values from the segment typedef SharedMemoryBuffer<int, ShmemAllocator> MyBuf; int main(int argc, char *argv[]) { shared_memory_object::remove("MySharedMemory"); //Create a new segment with given name and size managed_shared_memory segment(create_only, "MySharedMemory", 65536); //Initialize shared memory STL-compatible allocator const ShmemAllocator alloc_inst (segment.get_segment_manager()); //Construct a buffer named "MyBuffer" in shared memory with argument alloc_inst MyBuf *pBuf = segment.construct<MyBuf>("MyBuffer")(100, alloc_inst); } This gives me all kinds of compilation errors related to templates for the last statement. What am I doing wrong?

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  • Query on simple C++ threadpool implementation

    - by ticketman
    Stackoverflow has been a tremendous help to me and I'd to give something back to the community. I have been implementing a simple threadpool using the tinythread C++ portable thread library, using what I have learnt from Stackoverflow. I am new to thread programming, so not that comfortable with mutexes, etc. I have a question best asked after presenting the code (which runs quite well under Linux): // ThreadPool.h class ThreadPool { public: ThreadPool(); ~ThreadPool(); // Creates a pool of threads and gets them ready to be used void CreateThreads(int numOfThreads); // Assigns a job to a thread in the pool, but doesn't start the job // Each SubmitJob call will use up one thread of the pool. // This operation can only be undone by calling StartJobs and // then waiting for the jobs to complete. On completion, // new jobs may be submitted. void SubmitJob( void (*workFunc)(void *), void *workData ); // Begins execution of all the jobs in the pool. void StartJobs(); // Waits until all jobs have completed. // The wait will block the caller. // On completion, new jobs may be submitted. void WaitForJobsToComplete(); private: enum typeOfWorkEnum { e_work, e_quit }; class ThreadData { public: bool ready; // thread has been created and is ready for work bool haveWorkToDo; typeOfWorkEnum typeOfWork; // Pointer to the work function each thread has to call. void (*workFunc)(void *); // Pointer to work data void *workData; ThreadData() : ready(false), haveWorkToDo(false) { }; }; struct ThreadArgStruct { ThreadPool *threadPoolInstance; int threadId; }; // Data for each thread ThreadData *m_ThreadData; ThreadPool(ThreadPool const&); // copy ctor hidden ThreadPool& operator=(ThreadPool const&); // assign op. hidden // Static function that provides the function pointer that a thread can call // By including the ThreadPool instance in the void * parameter, // we can use it to access other data and methods in the ThreadPool instance. static void ThreadFuncWrapper(void *arg) { ThreadArgStruct *threadArg = static_cast<ThreadArgStruct *>(arg); threadArg->threadPoolInstance->ThreadFunc(threadArg->threadId); } // The function each thread calls void ThreadFunc( int threadId ); // Called by the thread pool destructor void DestroyThreadPool(); // Total number of threads available // (fixed on creation of thread pool) int m_numOfThreads; int m_NumOfThreadsDoingWork; int m_NumOfThreadsGivenJobs; // List of threads std::vector<tthread::thread *> m_ThreadList; // Condition variable to signal each thread has been created and executing tthread::mutex m_ThreadReady_mutex; tthread::condition_variable m_ThreadReady_condvar; // Condition variable to signal each thread to start work tthread::mutex m_WorkToDo_mutex; tthread::condition_variable m_WorkToDo_condvar; // Condition variable to signal the main thread that // all threads in the pool have completed their work tthread::mutex m_WorkCompleted_mutex; tthread::condition_variable m_WorkCompleted_condvar; }; cpp file: // // ThreadPool.cpp // #include "ThreadPool.h" // This is the thread function for each thread. // All threads remain in this function until // they are asked to quit, which only happens // when terminating the thread pool. void ThreadPool::ThreadFunc( int threadId ) { ThreadData *myThreadData = &m_ThreadData[threadId]; std::cout << "Hello world: Thread " << threadId << std::endl; // Signal that this thread is ready m_ThreadReady_mutex.lock(); myThreadData->ready = true; m_ThreadReady_condvar.notify_one(); // notify the main thread m_ThreadReady_mutex.unlock(); while(true) { //tthread::lock_guard<tthread::mutex> guard(m); m_WorkToDo_mutex.lock(); while(!myThreadData->haveWorkToDo) // check for work to do m_WorkToDo_condvar.wait(m_WorkToDo_mutex); // if no work, wait here myThreadData->haveWorkToDo = false; // need to do this before unlocking the mutex m_WorkToDo_mutex.unlock(); // Do the work switch(myThreadData->typeOfWork) { case e_work: std::cout << "Thread " << threadId << ": Woken with work to do\n"; // Do work myThreadData->workFunc(myThreadData->workData); std::cout << "#Thread " << threadId << ": Work is completed\n"; break; case e_quit: std::cout << "Thread " << threadId << ": Asked to quit\n"; return; // ends the thread } // Now to signal the main thread that my work is completed m_WorkCompleted_mutex.lock(); m_NumOfThreadsDoingWork--; // Unsure if this 'if' would make the program more efficient // if(NumOfThreadsDoingWork == 0) m_WorkCompleted_condvar.notify_one(); // notify the main thread m_WorkCompleted_mutex.unlock(); } } ThreadPool::ThreadPool() { m_numOfThreads = 0; m_NumOfThreadsDoingWork = 0; m_NumOfThreadsGivenJobs = 0; } ThreadPool::~ThreadPool() { if(m_numOfThreads) { DestroyThreadPool(); delete [] m_ThreadData; } } void ThreadPool::CreateThreads(int numOfThreads) { // Check a thread pool has already been created if(m_numOfThreads > 0) return; m_NumOfThreadsGivenJobs = 0; m_NumOfThreadsDoingWork = 0; m_numOfThreads = numOfThreads; m_ThreadData = new ThreadData[m_numOfThreads]; ThreadArgStruct threadArg; for(int i=0; i<m_numOfThreads; ++i) { threadArg.threadId = i; threadArg.threadPoolInstance = this; // Creates the thread and save in a list so we can destroy it later m_ThreadList.push_back( new tthread::thread( ThreadFuncWrapper, (void *)&threadArg ) ); // It takes a little time for a thread to get established. // Best wait until it gets established before creating the next thread. m_ThreadReady_mutex.lock(); while(!m_ThreadData[i].ready) // Check if thread is ready m_ThreadReady_condvar.wait(m_ThreadReady_mutex); // If not, wait here m_ThreadReady_mutex.unlock(); } } // Adds a job to the batch, but doesn't start the job void ThreadPool::SubmitJob(void (*workFunc)(void *), void *workData) { // Check that the thread pool has been created if(!m_numOfThreads) return; if(m_NumOfThreadsGivenJobs >= m_numOfThreads) return; m_ThreadData[m_NumOfThreadsGivenJobs].workFunc = workFunc; m_ThreadData[m_NumOfThreadsGivenJobs].workData = workData; std::cout << "Submitted job " << m_NumOfThreadsGivenJobs << std::endl; m_NumOfThreadsGivenJobs++; } void ThreadPool::StartJobs() { // Check that the thread pool has been created // and some jobs have been assigned if(!m_numOfThreads || !m_NumOfThreadsGivenJobs) return; // Set 'haveworkToDo' flag for all threads m_WorkToDo_mutex.lock(); for(int i=0; i<m_NumOfThreadsGivenJobs; ++i) m_ThreadData[i].haveWorkToDo = true; m_NumOfThreadsDoingWork = m_NumOfThreadsGivenJobs; // Reset this counter so we can resubmit jobs later m_NumOfThreadsGivenJobs = 0; // Notify all threads they have work to do m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); } void ThreadPool::WaitForJobsToComplete() { // Check that a thread pool has been created if(!m_numOfThreads) return; m_WorkCompleted_mutex.lock(); while(m_NumOfThreadsDoingWork > 0) // Check if all threads have completed their work m_WorkCompleted_condvar.wait(m_WorkCompleted_mutex); // If not, wait here m_WorkCompleted_mutex.unlock(); } void ThreadPool::DestroyThreadPool() { std::cout << "Ask threads to quit\n"; m_WorkToDo_mutex.lock(); for(int i=0; i<m_numOfThreads; ++i) { m_ThreadData[i].haveWorkToDo = true; m_ThreadData[i].typeOfWork = e_quit; } m_WorkToDo_condvar.notify_all(); m_WorkToDo_mutex.unlock(); // As each thread terminates, catch them here for(int i=0; i<m_numOfThreads; ++i) { tthread::thread *t = m_ThreadList[i]; // Wait for thread to complete t->join(); } m_numOfThreads = 0; } Example of usage: (this calculates pi-squared/6) struct CalculationDataStruct { int inputVal; double outputVal; }; void LongCalculation( void *theSums ) { CalculationDataStruct *sums = (CalculationDataStruct *)theSums; int terms = sums->inputVal; double sum; for(int i=1; i<terms; i++) sum += 1.0/( double(i)*double(i) ); sums->outputVal = sum; } int main(int argc, char** argv) { int numThreads = 10; // Create pool ThreadPool threadPool; threadPool.CreateThreads(numThreads); // Create thread workspace CalculationDataStruct sums[numThreads]; // Set up jobs for(int i=0; i<numThreads; i++) { sums[i].inputVal = 3000*(i+1); threadPool.SubmitJob(LongCalculation, &sums[i]); } // Run the jobs threadPool.StartJobs(); threadPool.WaitForJobsToComplete(); // Print results for(int i=0; i<numThreads; i++) std::cout << "Sum of " << sums[i].inputVal << " terms is " << sums[i].outputVal << std::endl; return 0; } Question: In the ThreadPool::ThreadFunc method, would better performance be obtained if the following if statement if(NumOfThreadsDoingWork == 0) was included? Also, I'd be grateful of criticisms and ways to improve the code. At the same time, I hope the code is of use to others.

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  • valgrind complains doing a very simple strtok in c

    - by monkeyking
    Hi I'm trying to tokenize a string by loading an entire file into a char[] using fread. For some strange reason it is not always working, and valgrind complains in this very small sample program. Given an input like test.txt first second And the following program #include <stdio.h> #include <string.h> #include <stdlib.h> #include <sys/stat.h> //returns the filesize in bytes size_t fsize(const char* fname){ struct stat st ; stat(fname,&st); return st.st_size; } int main(int argc, char *argv[]){ FILE *fp = NULL; if(NULL==(fp=fopen(argv[1],"r"))){ fprintf(stderr,"\t-> Error reading file:%s\n",argv[1]); return 0; } char buffer[fsize(argv[1])]; fread(buffer,sizeof(char),fsize(argv[1]),fp); char *str = strtok(buffer," \t\n"); while(NULL!=str){ fprintf(stderr,"token is:%s with strlen:%lu\n",str,strlen(str)); str = strtok(NULL," \t\n"); } return 0; } compiling like gcc test.c -std=c99 -ggdb running like ./a.out test.txt thanks

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  • forkpty - socket

    - by Alexxx
    Hi, I'm trying to develop a simple "telnet/server" daemon which have to run a program on a new socket connection. This part working fine. But I have to associate my new process to a pty, because this process have some terminal capabilities (like a readline). The code I've developped is (where socketfd is the new socket file descriptor for the new input connection) : int masterfd, pid; const char *prgName = "..."; char *arguments[10] = ....; if ((pid = forkpty(&masterfd, NULL, NULL, NULL)) < 0) perror("FORK"); else if (pid) return pid; else { close(STDOUT_FILENO); dup2(socketfd, STDOUT_FILENO); close(STDIN_FILENO); dup2(socketfd, STDIN_FILENO); close(STDERR_FILENO); dup2(socketfd, STDERR_FILENO); if (execvp(prgName, arguments) < 0) { perror("execvp"); exit(2); } } With that code, the stdin / stdout / stderr file descriptor of my "prgName" are associated to the socket (when looking with ls -la /proc/PID/fd), and so, the terminal capabilities of this process doesn't work. A test with a connection via ssh/sshd on the remote device, and executing "localy" (under the ssh connection) prgName, show that the stdin/stdout/stderr fd of this process "prgName" are associated to a pty (and so the terminal capabilities of this process are working fine). What I am doing wrong? How to associate my socketfd with the pty (created by forkpty) ? Thank Alex

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