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  • How does sizeof calculate the size of structures

    - by Gearoid Murphy
    I know that a char and an int are calculated as being 8 bytes on 32 bit architectures due to alignment, but I recently came across a situation where a structure with 3 shorts was reported as being 6 bytes by the sizeof operator. Code is as follows: #include <iostream> using namespace std ; struct IntAndChar { int a ; unsigned char b ; }; struct ThreeShorts { unsigned short a ; unsigned short b ; unsigned short c ; }; int main() { cout<<sizeof(IntAndChar)<<endl; // outputs '8' cout<<sizeof(ThreeShorts)<<endl; // outputs '6', I expected this to be '8' return 0 ; } Compiler : g++ (Debian 4.3.2-1.1) 4.3.2. This really puzzles me, why isn't alignment enforced for the structure containing 3 shorts?

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  • Play and record streaming audio

    - by Igor
    I'm working on an iPhone app that should be able to play and record audio streaming data simultaneously. Is it actually possible? I'm trying to mix SpeakHere and AudioRecorder samples and getting an empty file with no audio data... Here is my .m code: import "AzRadioViewController.h" @implementation azRadioViewController static const CFOptionFlags kNetworkEvents = kCFStreamEventOpenCompleted | kCFStreamEventHasBytesAvailable | kCFStreamEventEndEncountered | kCFStreamEventErrorOccurred; void MyAudioQueueOutputCallback( void* inClientData, AudioQueueRef inAQ, AudioQueueBufferRef inBuffer, const AudioTimeStamp inStartTime, UInt32 inNumberPacketDescriptions, const AudioStreamPacketDescription inPacketDesc ) { NSLog(@"start MyAudioQueueOutputCallback"); MyData* myData = (MyData*)inClientData; NSLog(@"--- %i", inNumberPacketDescriptions); if(inNumberPacketDescriptions == 0 && myData-dataFormat.mBytesPerPacket != 0) { inNumberPacketDescriptions = inBuffer-mAudioDataByteSize / myData-dataFormat.mBytesPerPacket; } OSStatus status = AudioFileWritePackets(myData-audioFile, FALSE, inBuffer-mAudioDataByteSize, inPacketDesc, myData-currentPacket, &inNumberPacketDescriptions, inBuffer-mAudioData); if(status == 0) { myData-currentPacket += inNumberPacketDescriptions; } NSLog(@"status:%i curpac:%i pcdesct: %i", status, myData-currentPacket, inNumberPacketDescriptions); unsigned int bufIndex = MyFindQueueBuffer(myData, inBuffer); pthread_mutex_lock(&myData-mutex); myData-inuse[bufIndex] = false; pthread_cond_signal(&myData-cond); pthread_mutex_unlock(&myData-mutex); } OSStatus StartQueueIfNeeded(MyData* myData) { NSLog(@"start StartQueueIfNeeded"); OSStatus err = noErr; if (!myData-started) { err = AudioQueueStart(myData-queue, NULL); if (err) { PRINTERROR("AudioQueueStart"); myData-failed = true; return err; } myData-started = true; printf("started\n"); } return err; } OSStatus MyEnqueueBuffer(MyData* myData) { NSLog(@"start MyEnqueueBuffer"); OSStatus err = noErr; myData-inuse[myData-fillBufferIndex] = true; AudioQueueBufferRef fillBuf = myData-audioQueueBuffer[myData-fillBufferIndex]; fillBuf-mAudioDataByteSize = myData-bytesFilled; err = AudioQueueEnqueueBuffer(myData-queue, fillBuf, myData-packetsFilled, myData-packetDescs); if (err) { PRINTERROR("AudioQueueEnqueueBuffer"); myData-failed = true; return err; } StartQueueIfNeeded(myData); return err; } void WaitForFreeBuffer(MyData* myData) { NSLog(@"start WaitForFreeBuffer"); if (++myData-fillBufferIndex = kNumAQBufs) myData-fillBufferIndex = 0; myData-bytesFilled = 0; myData-packetsFilled = 0; printf("-lock\n"); pthread_mutex_lock(&myData-mutex); while (myData-inuse[myData-fillBufferIndex]) { printf("... WAITING ...\n"); pthread_cond_wait(&myData-cond, &myData-mutex); } pthread_mutex_unlock(&myData-mutex); printf("<-unlock\n"); } int MyFindQueueBuffer(MyData* myData, AudioQueueBufferRef inBuffer) { NSLog(@"start MyFindQueueBuffer"); for (unsigned int i = 0; i < kNumAQBufs; ++i) { if (inBuffer == myData-audioQueueBuffer[i]) return i; } return -1; } void MyAudioQueueIsRunningCallback( void* inClientData, AudioQueueRef inAQ, AudioQueuePropertyID inID) { NSLog(@"start MyAudioQueueIsRunningCallback"); MyData* myData = (MyData*)inClientData; UInt32 running; UInt32 size; OSStatus err = AudioQueueGetProperty(inAQ, kAudioQueueProperty_IsRunning, &running, &size); if (err) { PRINTERROR("get kAudioQueueProperty_IsRunning"); return; } if (!running) { pthread_mutex_lock(&myData-mutex); pthread_cond_signal(&myData-done); pthread_mutex_unlock(&myData-mutex); } } void MyPropertyListenerProc( void * inClientData, AudioFileStreamID inAudioFileStream, AudioFileStreamPropertyID inPropertyID, UInt32 * ioFlags) { NSLog(@"start MyPropertyListenerProc"); MyData* myData = (MyData*)inClientData; OSStatus err = noErr; printf("found property '%c%c%c%c'\n", (inPropertyID24)&255, (inPropertyID16)&255, (inPropertyID8)&255, inPropertyID&255); switch (inPropertyID) { case kAudioFileStreamProperty_ReadyToProducePackets : { AudioStreamBasicDescription asbd; UInt32 asbdSize = sizeof(asbd); err = AudioFileStreamGetProperty(inAudioFileStream, kAudioFileStreamProperty_DataFormat, &asbdSize, &asbd); if (err) { PRINTERROR("get kAudioFileStreamProperty_DataFormat"); myData-failed = true; break; } err = AudioQueueNewOutput(&asbd, MyAudioQueueOutputCallback, myData, NULL, NULL, 0, &myData-queue); if (err) { PRINTERROR("AudioQueueNewOutput"); myData-failed = true; break; } for (unsigned int i = 0; i < kNumAQBufs; ++i) { err = AudioQueueAllocateBuffer(myData-queue, kAQBufSize, &myData-audioQueueBuffer[i]); if (err) { PRINTERROR("AudioQueueAllocateBuffer"); myData-failed = true; break; } } UInt32 cookieSize; Boolean writable; err = AudioFileStreamGetPropertyInfo(inAudioFileStream, kAudioFileStreamProperty_MagicCookieData, &cookieSize, &writable); if (err) { PRINTERROR("info kAudioFileStreamProperty_MagicCookieData"); break; } printf("cookieSize %d\n", cookieSize); void* cookieData = calloc(1, cookieSize); err = AudioFileStreamGetProperty(inAudioFileStream, kAudioFileStreamProperty_MagicCookieData, &cookieSize, cookieData); if (err) { PRINTERROR("get kAudioFileStreamProperty_MagicCookieData"); free(cookieData); break; } err = AudioQueueSetProperty(myData-queue, kAudioQueueProperty_MagicCookie, cookieData, cookieSize); free(cookieData); if (err) { PRINTERROR("set kAudioQueueProperty_MagicCookie"); break; } err = AudioQueueAddPropertyListener(myData-queue, kAudioQueueProperty_IsRunning, MyAudioQueueIsRunningCallback, myData); if (err) { PRINTERROR("AudioQueueAddPropertyListener"); myData-failed = true; break; } break; } } } static void ReadStreamClientCallBack(CFReadStreamRef stream, CFStreamEventType type, void *clientCallBackInfo) { NSLog(@"start ReadStreamClientCallBack"); if(type == kCFStreamEventHasBytesAvailable) { UInt8 buffer[2048]; CFIndex bytesRead = CFReadStreamRead(stream, buffer, sizeof(buffer)); if (bytesRead < 0) { } else if (bytesRead) { OSStatus err = AudioFileStreamParseBytes(globalMyData-audioFileStream, bytesRead, buffer, 0); if (err) { PRINTERROR("AudioFileStreamParseBytes"); } } } } void MyPacketsProc(void * inClientData, UInt32 inNumberBytes, UInt32 inNumberPackets, const void * inInputData, AudioStreamPacketDescription inPacketDescriptions) { NSLog(@"start MyPacketsProc"); MyData myData = (MyData*)inClientData; printf("got data. bytes: %d packets: %d\n", inNumberBytes, inNumberPackets); for (int i = 0; i < inNumberPackets; ++i) { SInt64 packetOffset = inPacketDescriptions[i].mStartOffset; SInt64 packetSize = inPacketDescriptions[i].mDataByteSize; size_t bufSpaceRemaining = kAQBufSize - myData-bytesFilled; if (bufSpaceRemaining < packetSize) { MyEnqueueBuffer(myData); WaitForFreeBuffer(myData); } AudioQueueBufferRef fillBuf = myData-audioQueueBuffer[myData-fillBufferIndex]; memcpy((char*)fillBuf-mAudioData + myData-bytesFilled, (const char*)inInputData + packetOffset, packetSize); myData-packetDescs[myData-packetsFilled] = inPacketDescriptions[i]; myData-packetDescs[myData-packetsFilled].mStartOffset = myData-bytesFilled; myData-bytesFilled += packetSize; myData-packetsFilled += 1; size_t packetsDescsRemaining = kAQMaxPacketDescs - myData-packetsFilled; if (packetsDescsRemaining == 0) { MyEnqueueBuffer(myData); WaitForFreeBuffer(myData); } } } (IBAction)buttonPlayPressedid)sender { label.text = @"Buffering"; [self connectionStart]; } (IBAction)buttonSavePressedid)sender { NSLog(@"save"); AudioFileClose(myData.audioFile); AudioQueueDispose(myData.queue, TRUE); } bool getFilename(char* buffer,int maxBufferLength) { NSArray paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString docDir = [paths objectAtIndex:0]; NSString* file = [docDir stringByAppendingString:@"/rec.caf"]; return [file getCString:buffer maxLength:maxBufferLength encoding:NSUTF8StringEncoding]; } -(void)connectionStart { @try { MyData* myData = (MyData*)calloc(1, sizeof(MyData)); globalMyData = myData; pthread_mutex_init(&myData-mutex, NULL); pthread_cond_init(&myData-cond, NULL); pthread_cond_init(&myData-done, NULL); NSLog(@"Start"); myData-dataFormat.mSampleRate = 16000.0f; myData-dataFormat.mFormatID = kAudioFormatLinearPCM; myData-dataFormat.mFramesPerPacket = 1; myData-dataFormat.mChannelsPerFrame = 1; myData-dataFormat.mBytesPerFrame = 2; myData-dataFormat.mBytesPerPacket = 2; myData-dataFormat.mBitsPerChannel = 16; myData-dataFormat.mReserved = 0; myData-dataFormat.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked; int i, bufferByteSize; UInt32 size; AudioQueueNewInput( &myData-dataFormat, MyAudioQueueOutputCallback, &myData, NULL /* run loop /, kCFRunLoopCommonModes / run loop mode /, 0 / flags */, &myData-queue); size = sizeof(&myData-dataFormat); AudioQueueGetProperty(&myData-queue, kAudioQueueProperty_StreamDescription, &myData-dataFormat, &size); CFURLRef fileURL; char path[256]; memset(path,0,sizeof(path)); getFilename(path,256); fileURL = CFURLCreateFromFileSystemRepresentation(NULL, (UInt8*)path, strlen(path), FALSE); AudioFileCreateWithURL(fileURL, kAudioFileCAFType, &myData-dataFormat, kAudioFileFlags_EraseFile, &myData-audioFile); OSStatus err = AudioFileStreamOpen(myData, MyPropertyListenerProc, MyPacketsProc, kAudioFileMP3Type, &myData-audioFileStream); if (err) { PRINTERROR("AudioFileStreamOpen"); return 1; } CFStreamClientContext ctxt = {0, self, NULL, NULL, NULL}; CFStringRef bodyData = CFSTR(""); // Usually used for POST data CFStringRef headerFieldName = CFSTR("X-My-Favorite-Field"); CFStringRef headerFieldValue = CFSTR("Dreams"); CFStringRef url = CFSTR(RADIO_LOCATION); CFURLRef myURL = CFURLCreateWithString(kCFAllocatorDefault, url, NULL); CFStringRef requestMethod = CFSTR("GET"); CFHTTPMessageRef myRequest = CFHTTPMessageCreateRequest(kCFAllocatorDefault, requestMethod, myURL, kCFHTTPVersion1_1); CFHTTPMessageSetBody(myRequest, bodyData); CFHTTPMessageSetHeaderFieldValue(myRequest, headerFieldName, headerFieldValue); CFReadStreamRef stream = CFReadStreamCreateForHTTPRequest(kCFAllocatorDefault, myRequest); if (!stream) { NSLog(@"Creating the stream failed"); return; } if (!CFReadStreamSetClient(stream, kNetworkEvents, ReadStreamClientCallBack, &ctxt)) { CFRelease(stream); NSLog(@"Setting the stream's client failed."); return; } CFReadStreamScheduleWithRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes); if (!CFReadStreamOpen(stream)) { CFReadStreamSetClient(stream, 0, NULL, NULL); CFReadStreamUnscheduleFromRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes); CFRelease(stream); NSLog(@"Opening the stream failed."); return; } } @catch (NSException *exception) { NSLog(@"main: Caught %@: %@", [exception name], [exception reason]); } } (void)viewDidLoad { [[UIApplication sharedApplication] setIdleTimerDisabled:YES]; [super viewDidLoad]; } (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; } (void)viewDidUnload { } (void)dealloc { [super dealloc]; } @end

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  • Creating .lib files in CUDA Toolkit 5

    - by user1683586
    I am taking my first faltering steps with CUDA Toolkit 5.0 RC using VS2010. Separate compilation has me confused. I tried to set up a project as a Static Library (.lib), but when I try to build it, it does not create a device-link.obj and I don't understand why. For instance, there are 2 files: A caller function that uses a function f #include "thrust\host_vector.h" #include "thrust\device_vector.h" using namespace thrust::placeholders; extern __device__ double f(double x); struct f_func { __device__ double operator()(const double& x) const { return f(x); } }; void test(const int len, double * data, double * res) { thrust::device_vector<double> d_data(data, data + len); thrust::transform(d_data.begin(), d_data.end(), d_data.begin(), f_func()); thrust::copy(d_data.begin(),d_data.end(), res); } And a library file that defines f __device__ double f(double x) { return x+2.0; } If I set the option generate relocatable device code to No, the first file will not compile due to unresolved extern function f. If I set it to -rdc, it will compile, but does not produce a device-link.obj file and so the linker fails. If I put the definition of f into the first file and delete the second it builds successfully, but now it isn't separate compilation anymore. How can I build a static library like this with separate source files? [Updated here] I called the first caller file "caller.cu" and the second "libfn.cu". The compiler lines that VS2010 outputs (which I don't fully understand) are (for caller): nvcc.exe -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.0\include" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.0\include" -G --keep-dir "Debug" -maxrregcount=0 --machine 32 --compile -g -D_MBCS -Xcompiler "/EHsc /W3 /nologo /Od /Zi /RTC1 /MDd " -o "Debug\caller.cu.obj" "G:\Test_Linking\caller.cu" -clean and the same for libfn, then: nvcc.exe -gencode=arch=compute_20,code=\"sm_20,compute_20\" --use-local-env --cl-version 2010 -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin" -rdc=true -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.0\include" -I"C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v5.0\include" -G --keep-dir "Debug" -maxrregcount=0 --machine 32 --compile -g -D_MBCS -Xcompiler "/EHsc /W3 /nologo /Od /Zi /RTC1 /MDd " -o "Debug\caller.cu.obj" "G:\Test_Linking\caller.cu" and again for libfn.

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  • Ok to use VirtualProtect to change resource in Delphi?

    - by user257188
    I'm working on a simple localization effort in D2010. I'm handling all strings on forms because ETM seems like overkill for my needs, as did other 3rd party tools... (although I'm not so sure at this point!) Is the code below for changing the Const.pas strings considered safe to change the button labels on standard message boxes? procedure HookResourceString(rs: PResStringRec; newStr: PChar); var oldprotect: DWORD; begin VirtualProtect(rs, SizeOf(rs^), PAGE_EXECUTE_READWRITE, @oldProtect); rs^.Identifier := Integer(newStr); VirtualProtect(rs, SizeOf(rs^), oldProtect, @oldProtect); end; const NewOK: PChar = 'New Ok'; NewCancel: PChar = 'New Cancel'; Procedure TForm.FormCreate; begin HookResourceString(@SMsgDlgOK, NewOK); HookResourceString(@SMsgDlgCancel, NewCancel); end;

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  • Problem with operator ==

    - by CPPDev
    I am facing some problem with use of operator == in the following c++ program. #include < iostream> using namespace std; class A { public: A(char *b) { a = b; } A(A &c) { a = c.a; } bool operator ==(A &other) { return strcmp(a, other.a); } private: char *a; }; int main() { A obj("test"); A obj1("test1"); if(obj1 == A("test1")) { cout<<"This is true"<<endl; } } What's wrong with if(obj1 == A("test1")) line ?? Any help is appreciated.

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  • using C function in C#

    - by andrew
    i have a dll, built with mingw one of the header files contains this: extern "C" { int get_mac_address(char * mac); //the function returns a mac address in the char * mac } I use this dll in another c++ app, built using Visual C++ (2008SP1), not managed, but plain c++ (simply include the header, and call the function) But now I have to use it in a C# application The problem is that i can't figure out how exactly (i'm new in .net programming) this is what i've tried public class Hwdinfo { [DllImport("mydll.dll")] public static extern void get_mac_address(string s); } When i call the function, nothing happens (the mydll.dll file is located in the bin folder of the c# app, and it gives me no errors or warnings whatsoever)

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  • Java: omitting a data member from the equals method.

    - by cchampion
    public class GamePiece { public GamePiece(char cLetter, int nPointValue) { m_cLetter=cLetter; m_nPointValue=nPointValue; m_nTurnPlaced=0; //has not been placed on game board yet. } public char GetLetter() {return m_cLetter;} public int GetPointValue() {return m_nPointValue;} public int GetTurnPlaced() {return m_nTurnPlaced;} public void SetTurnPlaced(int nTurnPlaced) { m_nTurnPlaced=nTurnPlaced; } @Override public boolean equals(Object obj) { /*NOTE to keep this shorter I omitted some of the null checking and instanceof stuff. */ GamePiece other = (GamePiece) obj; //not case sensitive, and I don`t think we want it to be here. if(m_cLetter != other.m_cLetter) { return false; } if(m_nPointValue != other.m_nPointValue) { return false; } /* NOTICE! m_nPointValue purposely omitted. It does not affect hashcode or equals */ return true; } @Override public int hashCode() { /* NOTICE! m_nPointValue purposely omitted. It should not affect hashcode or equals */ final int prime = 41; return prime * (prime + m_nPointValue + m_cLetter); } private char m_cLetter; private int m_nPointValue; private int m_nTurnPlaced;//turn which the game piece was placed on the game board. Does not affect equals or has code! } Consider the given piece of code. This object has been immutable until the introduction of the m_nTurnPlaced member (which can be modified by the SetTurnPlaced method, so now GamePiece becomes mutable). GamePiece is used in an ArrayList, I call contains and remove methods which both rely on the equals method to be implemented. My question is this, is it ok or common practice in Java for some members to not affect equals and hashcode? How will this affect its use in my ArrayList? What type of java Collections would it NOT be safe to use this object now that it is mutable? I've been told that you're not supposed to override equals on mutable objects because it causes some collections to behave "strangely" (I read that somewhere in the java documentation).

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  • QT clicked signal dosnt work on QStandardItemModel with tree view

    - by user63898
    Hello i have this code in QT and all i want to to catch the clicked event when some one clicking in one of the treeview rows without success here is my code: (parant is the qMmainwindow) m_model = new QStandardItemModel(0, 5, parent); // then later in the code i have proxyModel = new QSortFilterProxyModel; proxyModel->setDynamicSortFilter(true); setSourceModel(createMailModel(parent)); ui.treeView->setModel(proxyModel); ui.treeView->setSortingEnabled(true); ui.treeView->sortByColumn(4, Qt::DescendingOrder); // and my signal/slot looks like this but its not working //and im not getting eny clicked event fired connect(ui.treeView,SIGNAL(Clicked(const QModelIndex& ) ), this,SLOT( treeViewSelectedRow(const QModelIndex& ) ) ); also how can i debug QT signal/slots so i can see some debug massages printing when something is wrong ?

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  • make error in re-building ns2

    - by user3702405
    I have implemented a new routing protocol named AODV2 in ns-2.35. I am using ns-2.35 in fedora 13. All .cc files have a .o file with them that means recompilation is done. But I am getting an error in response to the 'make' command. Error is shown below: trace/cmu-trace.o: In function hdr_aodv2::access(Packet const*)': cmu-trace.cc:(.text._ZN9hdr_aodv26accessEPK6Packet[hdr_aodv2::access(Packet const*)]+0x7): undefined reference tohdr_aodv2::offset_2' collect2: ld returned 1 exit status make: * [ns] Error 1 I don't know how to remove this error, Can anyone help me please? Thanks, Naeem

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  • How to preserve struct member identifiers when compiling to LLVM IR with Clang?

    - by smokris
    Say I have the following C structure definition: struct stringStructure { char *stringVariable; }; For the above, Clang produces the following LLVM IR: %struct.stringStructure = type { i8* } ...which includes everything in my definition except the variable identifier stringVariable. I'd like to find some way to export the identifier into the generated LLVM IR, so that I can refer to it by name from my application (which uses the LLVM C++ API). I've tried adding the annotate attribute, as follows: char *stringVariable __attribute__((annotate("stringVariable"))); ...but the annotation doesn't seem to make it through (the structure is still just defined as type { i8* }). Any ideas?

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  • memory alignment issues with union

    - by confucius
    Hi all, Is there guarantee, that memory for this object will be properly aligned if we create this object of this type in stack? union my_union { int value; char bytes[4]; }; If we create char bytes[4] in stack and then try to cast it to integer there might be alignment problem. We can avoid that problem by creating it in heap, however, is there such guarantee for union objects? Logically there should be, but I would like to confirm. Thanks.

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  • warning in Eclipse

    - by lego69
    hello, I have some problems with Eclipse, I have structure struct Account{ const char* strLastName; //Client's last name const char* strFirstName; //Client's first name int nID; //Client's ID number int nLines; //Number of lines related to account double lastBill; //Client's last bill for all lines List linesDataBase; }; And I can't compile my code eclipse gives me an errors: Syntax error before List no semicolon at end of struct or union ISO does not allow extra ";" outside a function I have no idea how to change it, thanks in advance for any help

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  • Force CL-Lex to read whole word

    - by Flávio Cruz
    I'm using CL-Lex to implement a lexer (as input for CL-YACC) and my language has several keywords such as "let" and "in". However, while the lexer recognizes such keywords, it does too much. When it finds words such as "init", it returns the first token as IN, while it should return a "CONST" token for the "init" word. This is a simple version of the lexer: (define-string-lexer lexer (...) ("in" (return (values :in $@))) ("[a-z]([a-z]|[A-Z]|\_)" (return (values :const $@)))) How do I force the lexer to fully read the whole word until some whitespace appears?

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  • Another C datatypes question

    - by b-gen-jack-o-neill
    Hello. Well, I completely get the most basic datatypes of C, like short, int, long, float, to be exact, all numerical types.These types are needed to be known perform right operations with right numbers. For example to use FPU to add two float numbers. So the compiler must know what the type is. But, when it comes to characters I am little bit off. I know that basic C datatype char is there for ASCII characters coding. But what I don´t know is, why you even need another datatype for characters. Why could not you just use 1 byte integer value to store ASCII character. If you call printf, you apecify the datatype in the call, so you could say to printf that the integer represents ASCII character. I dont know how cout resolves datatype, but I guess you could just specify it somehow. Another thing is, when you want to use Unicode, you must use datatype wchar. But, what if I would like to use some another, for example ISO, or Windows coding instead of UTF? Becouse wchar codes characters as UTF-16 or UTF-32 (I read its compiler specific). And, what if I would want to use for example some imaginary new 8 byte text coding? What datatype should I use for it? I am actually pretty confused of this, becouse I always expected that if I want to use UTF-32 instead of ASCII, I just tell compiler "get UTF-32 value of the character I typed and save it into 4 char field." I thought that text coding is to be dealt with by the end, print function for example. That I just need to specify the coding for the compiler to use, since Windows doesent use ASCII in win32 apps, I guess C compiler must convert the char I typed to ASCII from whatever the type is that windows sends to the C editor. And the last thing is, what if I want to use for example 25 Byte integer for some high math operations? C has no specify-yourself datatype. Yes, I know that this would be difficult since all the math operations would need to be changed, becouse CPU can not add 25 Bytes numbers together. But is there a way to do it? Or is there some math library for it? What if I want to compute Pi to 1000000000000000 digits? :) I know my question is pretty long, but I just wanted to explain my thoughts the best I can in English, since its not my native language it is difficult. And I believe there is simple answer to my question(s), something I missed that explains everything. I read lot about text coding, C tutorials, but nothing about his. Thank you for your time.

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  • Similar route mapping

    - by Denis Agarev
    I need to map to create controller what must response to two urls: "http://localhost/api/controller?id=1" (where only id value can change) "http://localhost/api/controller/anotherId/someconst" (where anotherId is the only one changing part) i map it to such route: routes.MapHttpRoute("Test", "api/{controller}/{id}/{someconst}", new { controller = "Test", someconst = RouteParameter.Optional }); And have to methods in my controller: public void Get(int id) { ... } public void Get(int anotherId, string someconst ) { ... } It works...But it doesn't look nice...cause "string someconst" is not a param, it's just a const part of url. But if i remove "string someconst" param second url wouldn't work. Is it possible to map one controller to two routes to resolve this urls to make it clear without fake param which is a const in fact?

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  • C#. Whats the fastest way to make an integer positive

    - by maxima120
    I asked wrong question previously and was swamped with negative votes... Let me try again... What is absolutely fastest way to make an int positive (given 50/50 distribution of pos/neg over time). To be nominated for an answer I will require MSIL analysis and not a guess or measuring of time with granny's watch... P.S. as one of variations I proposed i * i not because I wanted to do Sqrt(i * i) afterwards but because i will be used only once to be compared to a const. And if i * i will win competition I simply multiply the const.. Hence the following solution is valid: int trigger = realTrigger * realTrigger; i = SomeCalcs(); i = i * i; if(i < trigger) DoSomething(); P.P.S. pointless rant is not acceptable.. like: why do you need this, its BS! C# cannot tolerate developers like you!

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  • QGraphicsItem repaint

    - by onurozcelik
    I want to change text color inside a rectangle periyodically Here is my trial: TrainIdBox::TrainIdBox() { boxRect = QRectF(0,0,40,15); testPen = QPen(Qt:red); i=0; startTimer(500); } QRectF TrainIdBox::boundingRect() const { return boxRect; } void TrainIdBox::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { Q_UNUSED(widget); Q_UNUSED(option); painter->setPen(QPen(drawingColor,2)); painter->drawRect(boxRect); painter->setPen(testPen); painter->drawText(boxRect,Qt::AlignCenter,"TEST"); } void TrainIdBox::timerEvent(QTimerEvent *te) { testPen = i % 2 == 0 ? QPen(Qt::green) : QPen(Qt::yellow); i++; update(boxRect); } This code does not working properly. What is wrong?

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  • C++ Linux getpeername IP family

    - by gln
    hi In my Linux C++ application I'm using getpeername in order to get the peer IP. my problem is: when I enable the IPv6 on my machine the IP I got from the peer is with family IF_INET6 although it is IPv4. code: int GetSockPeerIP( int sock) { struct sockaddr_storage ss; struct socklen_t salen = sizeof(ss); struct sockaddr *sa; memset(&ss,0,salen); sa = (sockaddr *)&ss; if(getpeername(sock,sa,&salen) != 0) { return -1; } char * ip=NULL: if(sa->sa_family == AF_INET) { ip = inet_ntoa((struct sockaddr_in *)sa)->sin_addr); } else { //ip = how to convert IPv6 to char IP? } return 0; } how can I fix it? thanks1

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  • PowerShell 2.0 and how to handle exceptions ?

    - by Primoz
    Why I get error message printed on the console when running these two simple samples ? I want that I get "Error testing :)" printed on the console insted of: Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA) At line:3 char:15 + Get-WmiObject <<<< -ComputerName possibly.nonexisting.domain.com -Credential (Get-Credential) -Class Win32_logicaldisk + CategoryInfo : InvalidOperation: (:) [Get-WmiObject], COMException + FullyQualifiedErrorId : GetWMICOMException,Microsoft.PowerShell.Commands.GetWmiObjectCommand or Attempted to divide by zero. At line:3 char:13 + $i = 1/ <<<< 0 + CategoryInfo : NotSpecified: (:) [], ParentContainsErrorRecordException + FullyQualifiedErrorId : RuntimeException First example: try { $i = 1/0 Write-Host $i } catch [Exception] { Write-Host "Error testing :)" } Second example: try { Get-WmiObject -ComputerName possibly.nonexisting.domain.com -Credential (Get-Credential) -Class Win32_logicaldisk } catch [Exception] { Write-Host "Error testing :)" } Thank you very much!

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  • stl::map insert segmentation fault

    - by Jakub Czaplicki
    Why does this code stop with the segmentation fault : class MapFile { public: /* ... */ std::map <unsigned int, unsigned int> inToOut; }; bool SwitchMapFile::LoadMapFile( const wxString& fileName ) { /* ... */ inToOut.insert( std::make_pair(spmPort,fibreId) ); } but this one works fine : class MapFile { public: /* ... */ }; bool MapFile::LoadMapFile( const wxString& fileName ) { /* ... */ std::map <unsigned int, unsigned int> inToOut; inToOut.insert( std::make_pair(input,output) ); } ?

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  • create program in c for permutation combination and showing frequency

    - by Vishal Oswal
    I have 2 strings where I have saved fixed 20 characters and these are “A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T” and same 20 char in string 2. so I will get 400 combinations of 2 character sets like AA,AB,AC,AD,AE,AF,……………AT BA,BB,BC,BD,BE,BF,…………..BT CA,CB,CC,CD,CE,CF……………CT This way we will get 400 combinations (Which program I have created successfully) but then user will put the value till 31 characters witch will be treated as 3rd string for E.g. “ABCDDAAAB” now I have to check the frequency of user input in the sequence of 12,23,34,45,56,67,78,89 (2 CHAR SET) means AB,BC,CD,DD,DA,AA,AA,AB and need to show the frequency of user input OUTPUT: AB=2 BC=1 CD=1 DD=1 DA=1 AA=2 please its urgent

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  • need identical string comparison function in php and java

    - by steelbytes
    I have sorted list of strings that I move between php and java. to be able to bsearch on this data, I need the same comparison function. any idea what string compare functions I can use that will always give the same result in both? eg php's strcmp() vs java's String.compareTo() yes I know I could make my own string compare that does char by char carefully, but I was hoping there's a simple answer. PS, don't care if case sensitive or not, as long as it is consistant.

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  • Cocoa multiple threads, locks don't work

    - by Igor
    I have a threadMethod which shows in console robotMotorsStatus every 0.5 sec. But when I try to change robotMotorsStatus in changeRobotStatus method I receive an exception. Where I need to put locks in that program. #import "AppController.h" @implementation AppController extern char *robotMotorsStatus; - (IBAction)runThread:(id)sender { [self performSelectorInBackground:@selector(threadMethod) withObject:nil]; } - (void)threadMethod { char string_to_send[]="QFF001100\r"; //String prepared to the port sending (first inintialization) string_to_send[7] = robotMotorsStatus[0]; string_to_send[8] = robotMotorsStatus[1]; while(1){ [theLock lock]; usleep(500000); NSLog (@"Robot status %s", robotMotorsStatus); [theLock unlock]; } } - (IBAction)changeRobotStatus:(id)sender { robotMotorsStatus[0]='1'; }

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  • How come this image won't resize to fit the sprite?

    - by George Edison
    I have this snippet of ActionScript code that is supposed to resize an image to fit the sprite: package { import flash.display.Sprite; import flash.display.Bitmap; import flash.events.Event; public class Main extends Sprite { [Embed(source = 'img.png')] private var TheImage:Class; public static const TheImageWidth:Number = 1300; public static const TheImageHeight:Number = 1300; public function Main():void { if (stage) init(); else addEventListener(Event.ADDED_TO_STAGE, init); } private function init(e:Event = null):void { removeEventListener(Event.ADDED_TO_STAGE, init); // entry point var image:Bitmap = new TheImage(); addChild(image); image.scaleX = width / TheImageWidth; image.scaleY = height / TheImageHeight; } } } Why isn't it working?

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  • PInvokeStackImbalance C# call to unmanaged C++ function

    - by user287498
    After switching to VS2010, the managed debug assistant is displaying an error about an unbalanced stack from a call to an unmanaged C++ function from a C# application. The usuals suspects don't seem to be causing the issue. Is there something else I should check? The VS2008 built C++ dll and C# application never had a problem, no weird or mysterious bugs - yeah, I know that doesn't mean much. Here are the things that were checked: The dll name is correct. The entry point name is correct and has been verified with depends.exe - the code has to use the mangled name and it does. The calling convention is correct. The sizes and types all seem to be correct. The character set is correct. There doesn't seem to be any issues after ignoring the error and there isn't an issue when running outside the debugger. C#: [DllImport("Correct.dll", EntryPoint = "SuperSpecialOpenFileFunc", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi, ExactSpelling = true)] public static extern short SuperSpecialOpenFileFunc(ref SuperSpecialStruct stuff); [StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Ansi)] public struct SuperSpecialStruct { public int field1; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)] public string field2; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 20)] public string field3; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)] public string field4; public ushort field5; public ushort field6; public ushort field7; public short field8; public short field9; public uint field10; public short field11; }; C++: short SuperSpecialOpenFileFunc(SuperSpecialStruct * stuff); struct SuperSpecialStruct { int field1; char field2[256]; char field3[20]; char field4[10]; unsigned short field5; unsigned short field6; unsigned short field7; short field8; short field9; unsigned int field10; short field11; }; Here is the error: Managed Debugging Assistant 'PInvokeStackImbalance' has detected a problem in 'Managed application path'. Additional Information: A call to PInvoke function 'SuperSpecialOpenFileFunc' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.

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