Search Results

Search found 7500 results on 300 pages for 'const char'.

Page 149/300 | < Previous Page | 145 146 147 148 149 150 151 152 153 154 155 156  | Next Page >

  • C++ cin questions

    - by Kim
    This seems to be weird: int main(int argc, char* argv[]) { cout << "function main() .." << '\n'; char ch = 0; double number_value=1.1; cin >> ch; cin.putback(ch); cin >> number_value; cout << "1 .. " << " " << cin.good() << " " << number_value << '\n'; cin >> number_value; cout << "2 .. " << " " << cin.good() << " " << number_value << '\n'; return 0; } If I input the following: 7a 1 I get the following: function main() .. 7a 1 1 .. 1 7 2 .. 0 0 I understand the: 1 .. 1 7 but why the variable number_value is 0. cin.good() shows failure so nothing would have read and the value in number_value from the previous assignment would remain. I expect the value of 7.

    Read the article

  • SQL Query to return maximums over decades

    - by Abraham Lincoln
    My question is the following. I have a baseball database, and in that baseball database there is a master table which lists every player that has ever played. There is also a batting table, which tracks every players' batting statistics. I created a view to join those two together; hence the masterplusbatting table. CREATE TABLE `Master` ( `lahmanID` int(9) NOT NULL auto_increment, `playerID` varchar(10) NOT NULL default '', `nameFirst` varchar(50) default NULL, `nameLast` varchar(50) NOT NULL default '', PRIMARY KEY (`lahmanID`), KEY `playerID` (`playerID`), ) ENGINE=MyISAM AUTO_INCREMENT=18968 DEFAULT CHARSET=latin1; CREATE TABLE `Batting` ( `playerID` varchar(9) NOT NULL default '', `yearID` smallint(4) unsigned NOT NULL default '0', `teamID` char(3) NOT NULL default '', `lgID` char(2) NOT NULL default '', `HR` smallint(3) unsigned default NULL, PRIMARY KEY (`playerID`,`yearID`,`stint`), KEY `playerID` (`playerID`), KEY `team` (`teamID`,`yearID`,`lgID`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; Anyway, my first query involved finding the most home runs hit every year since baseball began, including ties. The query to do that is the following.... select f.yearID, f.nameFirst, f.nameLast, f.HR from ( select yearID, max(HR) as HOMERS from masterplusbatting group by yearID )as x inner join masterplusbatting as f on f.yearID = x.yearId and f.HR = x.HOMERS This worked great. However, I now want to find the highest HR hitter in each decade since baseball began. Here is what I tried. select f.yearID, truncate(f.yearid/10,0) as decade,f.nameFirst, f.nameLast, f.HR from ( select yearID, max(HR) as HOMERS from masterplusbatting group by yearID )as x inner join masterplusbatting as f on f.yearID = x.yearId and f.HR = x.HOMERS group by decade You can see that I truncated the yearID in order to get 187, 188, 189 etc instead of 1897, 1885,. I then grouped by the decade, thinking that it would give me the highest per decade, but it is not returning the correct values. For example, it's giving me Adrian Beltre with 48 HR's in 2004 but everyone knows that Barry Bonds hit 73 HR in 2001. Can anyone give me some pointers?

    Read the article

  • Detecting Inheritence during compile time

    - by Jagannath
    I am unable to figure out why this code is returning false. I had the first version of partial specialization. It did not work, I tried with the second version. It did not work either. UPDATE: I wanted to check if "Derived" is publicly derived from "Base". template<class TBase, class TDerived> struct IsDerived { public: enum { isDerived = false }; }; template<class TBase> struct IsDerived<TBase, TBase> { public: enum { isDerived = true }; }; template<class TBase> struct IsDerived<TBase&, TBase&> { public: enum { isDerived = true }; }; int main() { cout << ((IsDerived<Base&, Derived&>::isDerived) ? "true" : "false") << endl; cout << ((IsDerived<const Derived*, const Base*>::isDerived) ? "true" : "false") << endl; }

    Read the article

  • visual studio macro - copy a definition or declaration from/to .h to/from .cpp

    - by Michael
    Is it possible to do a macro that copies a definition of a function to a declaration, and also the opposite? For instance class Foo { Foo(int aParameter, int aDefaultParameter = 0); int someMethod(char aCharacter) const; }; from the .h file would be: Foo::Foo(int aParameter, int aDefaultParameter){ // } int Foo::someMethod(char aCharacter) const { return 0; } in the .cpp file. The opposite wouldn't work with the default value, but it would still be cool if it copied the declaration into the class in the header file. Also if it could return a default value as in someMethod (based on the return value from the declaration). Personally I tried to do macrocoding some year ago (I think it was around 2005) but the tutorials and documentation of macros was thin (or I hadn't searched enough). I ended up going through the examples that they had in the IDE but gave up when I figured it would take too long to learn. I would however like to give it a try again. So if there are anyone with knowledge of good tutorials or documentation that aims at Visual Studio .Net (and maybe also covers the above problem) I would probably accept that as an answer as well :)

    Read the article

  • Linker error: wants C++ virtual base class destructor

    - by jdmuys
    Hi, I have a link error where the linker complains that my concrete class's destructor is calling its abstract superclass destructor, the code of which is missing. This is using GCC 4.2 on Mac OS X from XCode. I saw http://stackoverflow.com/questions/307352/g-undefined-reference-to-typeinfo but it's not quite the same thing. Here is the linker error message: Undefined symbols: "ConnectionPool::~ConnectionPool()", referenced from: AlwaysConnectedConnectionZPool::~AlwaysConnectedConnectionZPool()in RKConnector.o ld: symbol(s) not found collect2: ld returned 1 exit status Here is the abstract base class declaration: class ConnectionPool { public: static ConnectionPool* newPool(std::string h, short p, std::string u, std::string pw, std::string b); virtual ~ConnectionPool() =0; virtual int keepAlive() =0; virtual int disconnect() =0; virtual sql::Connection * getConnection(char *compression_scheme = NULL) =0; virtual void releaseConnection(sql::Connection * theConnection) =0; }; Here is the concrete class declaration: class AlwaysConnectedConnectionZPool: public ConnectionPool { protected: <snip data members> public: AlwaysConnectedConnectionZPool(std::string h, short p, std::string u, std::string pw, std::string b); virtual ~AlwaysConnectedConnectionZPool(); virtual int keepAlive(); // will make sure the connection doesn't time out. Call regularly virtual int disconnect(); // disconnects/destroys all connections. virtual sql::Connection * getConnection(char *compression_scheme = NULL); virtual void releaseConnection(sql::Connection * theConnection); }; Needless to say, all those members are implemented. Here is the destructor: AlwaysConnectedConnectionZPool::~AlwaysConnectedConnectionZPool() { printf("AlwaysConnectedConnectionZPool destructor call"); // nothing to destruct in fact } and also maybe the factory routine: ConnectionPool* ConnectionPool::newPool(std::string h, short p, std::string u, std::string pw, std::string b) { return new AlwaysConnectedConnectionZPool(h, p, u, pw, b); } I can fix this by artificially making my abstract base class concrete. But I'd rather do something better. Any idea? Thanks

    Read the article

  • Pthread-ed filetransfer application crash

    - by N.R.S.Sowrabh
    I am developing a file transfer application and am using pthreads on the receiver side for receiving multiple files. The function which is passed to pthreads calls the following function and at the end of this function I get a SIGABRT error and stack-smashing error appears on the terminal. Please help me find the bugs. If you need anymore code I'd be able to post the same. Thanks in advance. void recv_mesg(int new_sockid, char *fname) { cout<<"New Thread created with "<<new_sockid<<" and "<<fname<<endl; char buf[MAXLINE]; int fd; fd = open(fname, O_WRONLY ); int len =0; while (len<1024) { int curr = recv(new_sockid, buf, 1024-len, 0); //fprintf(stdout,"Message from Client:\n"); len += curr; //write (fd, buf, curr); fputs(buf, stderr); } int file_size = 0; sscanf(buf,"%d",&file_size); if(file_size<=0) perror("File Size < 0"); sprintf(buf,"Yes"); send(new_sockid,buf,strlen(buf),0); len = 0; while (len<file_size) { int curr = recv(new_sockid, buf, min(file_size-len,MAXLINE), 0); len += curr; write (fd, buf, curr); //fputs(buf, stdout); //fflush(stdout); } len = 0; close(fd); close(new_sockid); }

    Read the article

  • problem with fork()

    - by john
    I'm writing a shell which forks, with the parent reading the input and the child process parsing and executing it with execvp. pseudocode of main method: do{ pid = fork(); print pid; if (p<0) { error; exit; } if (p>0) { wait for child to finish; read input; } else { call function to parse input; exit; } }while condition return; what happens is that i never seem to enter the child process (pid printed is always positive, i never enter the else). however, if i don't call the parse function and just have else exit, i do correctly enter parent and child alternatingly. full code: int main(int argc, char *argv[]){ char input[500]; pid_t p; int firstrun = 1; do{ p = fork(); printf("PID: %d", p); if (p < 0) {printf("Error forking"); exit(-1);} if (p > 0){ wait(NULL); firstrun = 0; printf("\n> "); bzero(input, 500); fflush(stdout); read(0, input, 499); input[strlen(input)-1] = '\0'; } else exit(0); else { if (parse(input) != 0 && firstrun != 1) { printf("Error parsing"); exit(-1); } exit(0); } }while(strcmp(input, "exit") != 0); return 0; }

    Read the article

  • SQL using sum to count results of multiple subqueries

    - by asdas
    I have a table with 2 columns: integer and var char. I am given only the integer values but need to do work on the var char (string) values. Given an integer, and a list of other integers (no overlap), I want to find the string for that single integer. Then I want to take that string and do the INSTR command with that string, and all the other strings for all the other integers. Then I want the sum of all the INSTR so the result is one number. So lets say I have int x, and list y=[y0, y1, y2]. I want to do 3 INSTR commands like SUM(INSTR(string for x, string for y0), INSTR(string for x, string for y1), INSTR(string for x, string for y2)) I think im going in the wrong direction, this is what I have. Im not good with sub queries. SELECT SUM ( SELECT INSTR ( SELECT string FROM pages WHERE int=? LIMIT 1, ( SELECT string FROM pages WHERE id=? OR id=? OR id=? LIMIT 3 ) ) )

    Read the article

  • Crash generated during destruction of hash_map

    - by Alien01
    I am using hash_map in application as typedef hash_map<DWORD,CComPtr<IInterfaceXX>> MapDword2Interface; In main application I am using static instance of this map static MapDword2Interface m_mapDword2Interface; I have got one crash dump from one of the client machines which point to the crash in clearing this map I opened that crash dump and here is assembly during debugging > call std::list<std::pair<unsigned long const ,ATL::CComPtr<IInterfaceXX> >,std::allocator<std::pair<unsigned long const ,ATL::CComPtr<IInterfaceXX> > > >::clear > mov eax,dword ptr [CMainApp::m_mapDword2Interface+8 (49XXXXX)] Here is code where crash dump is pointing. Below code is from stl:list file void clear() { // erase all #if _HAS_ITERATOR_DEBUGGING this->_Orphan_ptr(*this, 0); #endif /* _HAS_ITERATOR_DEBUGGING */ _Nodeptr _Pnext; _Nodeptr _Pnode = _Nextnode(_Myhead); _Nextnode(_Myhead) = _Myhead; _Prevnode(_Myhead) = _Myhead; _Mysize = 0; for (; _Pnode != _Myhead; _Pnode = _Pnext) { // delete an element _Pnext = _Nextnode(_Pnode); this->_Alnod.destroy(_Pnode); this->_Alnod.deallocate(_Pnode, 1); } } Crash is pointing to the this->_Alnod.destroy(_Pnode); statement in above code. I am not able to guess it, what could be reason. Any ideas??? How can I make sure, even is there is something wrong with the map , it should not crash?

    Read the article

  • Returning object from function

    - by brainydexter
    I am really confused now on how and which method to use to return object from a function. I want some feedback on the solutions for the given requirements. Scenario A: The returned object is to be stored in a variable which need not be modified during its lifetime. Thus, const Foo SomeClass::GetFoo() { return Foo(); } invoked as: someMethod() { const Foo& l_Foo = someClassPInstance->GetFoo(); //... } Scneraio B: The returned object is to be stored in a variable which will be modified during its lifetime. Thus, void SomeClass::GetFoo(Foo& a_Foo_ref) { a_Foo_ref = Foo(); } invoked as: someMethod() { Foo l_Foo; someClassPInstance-GetFoo(l_Foo); //... } I have one question here: Lets say that Foo cannot have a default constructor. Then how would you deal with that in this situation, since we cant write this anymore: Foo l_Foo Scenario C: Foo SomeClass::GetFoo() { return Foo(); } invoked as: someMethod() { Foo l_Foo = someClassPInstance->GetFoo(); //... } I think this is not the recommended approach since it would incur constructing extra temporaries. What do you think ? Also, do you recommend a better way to handle this instead ?

    Read the article

  • No output got after execution.

    - by wilson88
    I am still stuck with getting output for a copied vector. Probably something am not doing right. I get no output. void Auctioneer::accept_bids(const BidList& bid){ BidList list; BidList list2; BidList::const_iterator iter; copy (list.begin(),list.end(), back_inserter(list2)); for(iter=list2.begin(); iter != list2.end(); iter++) { const Bid& bid = *iter; // Get a reference to the Bid object that the iterator points to cout << "Bid id : " << bid.bidId << endl; cout << "Trd id : " << bid.trdId << endl; cout << "Quantity: " << bid.qty << endl; cout << "Price : " << bid.price << endl; cout << "Type : " << bid.type << endl; } }

    Read the article

  • Printing a field with additional dots in haskell

    - by Frank Kluyt
    I'm writing a function called printField. This function takes an int and a string as arguments and then then prints a field like this "Derp..." with this: printField 7 "Derp". When the field consists of digits the output should be "...3456". The function I wrote looks like this: printField :: Int -> String -> String printField x y = if isDigit y then concat(replicate n ".") ++ y else y ++ concat(replicate n ".") where n = x - length y This obviously isn't working. The error I get from GHC is: Couldn't match type `[Char]' with `Char' Expected type: Char Actual type: String In the first argument of `isDigit', namely `y' In the expression: isDigit y In the expression: if isDigit y then concat (replicate n ".") ++ y else y ++ concat (replicate n ".") I can't get it to work :(. Can anyone help me out? Please keep in mind that I'm new to Haskell and functional programming in general.

    Read the article

  • How to give a textbox a fixed width of 17,5 cm?

    - by Natrium
    I have an application with a textbox, and the width of the textbox on the screen must always be 17,5 centimeters on the screen of the user. This is what I tried so far: const double centimeter = 17.5; // the width I need const double inches = centimeter * 0.393700787; // convert centimeter to inches float dpi = GetDpiX(); // get the dpi. 96 in my case. var pixels = dpi*inches; // this should give me the amount of pixels textbox1.Width = Convert.ToInt32(pixels); // set it. Done. private float GetDpiX() { floar returnValue; Graphics graphics = CreateGraphics(); returnValue = graphics.DpiX; graphics.Dispose(); // don’t forget to release the unnecessary resources return returnValue; } But this gives me different sizes with different resolutions. It gives me 13 cm with 1680 x 1050 and 19,5 cm with 1024 x 768. What am I doing wrong?

    Read the article

  • Why MSMQ won't send a space character?

    - by cyclotis04
    I'm exploring MSMQ services, and I wrote a simple console client-server application that sends each of the client's keystrokes to the server. Whenever hit a control character (DEL, ESC, INS, etc) the server understandably throws an error. However, whenever I type a space character, the server receives the packet but doesn't throw an error and doesn't display the space. Server: namespace QIM { class Program { const string QUEUE = @".\Private$\qim"; static MessageQueue _mq; static readonly object _mqLock = new object(); static XmlSerializer xs; static void Main(string[] args) { lock (_mqLock) { if (!MessageQueue.Exists(QUEUE)) _mq = MessageQueue.Create(QUEUE); else _mq = new MessageQueue(QUEUE); } xs = new XmlSerializer(typeof(string)); _mq.BeginReceive(new TimeSpan(0, 1, 0), new object(), OnReceive); while (Console.ReadKey().Key != ConsoleKey.Escape) { } } static void OnReceive(IAsyncResult result) { Message msg; lock (_mqLock) { try { msg = _mq.EndReceive(result); Console.Write("."); Console.Write(xs.Deserialize(msg.BodyStream)); } catch (Exception ex) { Console.Write(ex); } } _mq.BeginReceive(new TimeSpan(0, 1, 0), new object(), OnReceive); } } } Client: namespace QIM_Client { class Program { const string QUEUE = @".\Private$\qim"; static MessageQueue _mq; static void Main(string[] args) { if (!MessageQueue.Exists(QUEUE)) _mq = MessageQueue.Create(QUEUE); else _mq = new MessageQueue(QUEUE); ConsoleKeyInfo key = new ConsoleKeyInfo(); while (key.Key != ConsoleKey.Escape) { key = Console.ReadKey(); _mq.Send(key.KeyChar.ToString()); } } } } Client Input: Testing, Testing... Server Output: .T.e.s.t.i.n.g.,..T.e.s.t.i.n.g...... You'll notice that the space character sends a message, but the character isn't displayed.

    Read the article

  • Android AES and init vector

    - by Donald_W
    I have an issue with AES encryptio and decryption: I can change my IV entirely and still I'm able to decode my data. public static final byte[] IV = { 65, 1, 2, 23, 4, 5, 6, 7, 32, 21, 10, 11, 12, 13, 84, 45 }; public static final byte[] IV2 = { 65, 1, 2, 23, 45, 54, 61, 81, 32, 21, 10, 121, 12, 13, 84, 45 }; public static final byte[] KEY = { 0, 42, 2, 54, 4, 45, 6, 7, 65, 9, 54, 11, 12, 13, 60, 15 }; public static final byte[] KEY2 = { 0, 42, 2, 54, 43, 45, 16, 17, 65, 9, 54, 11, 12, 13, 60, 15 }; //public static final int BITS = 256; public static void test() { try { // encryption Cipher c = Cipher.getInstance("AES"); SecretKeySpec keySpec = new SecretKeySpec(KEY, "AES"); c.init(Cipher.ENCRYPT_MODE, keySpec, new IvParameterSpec(IV)); String s = "Secret message"; byte[] data = s.getBytes(); byte[] encrypted = c.doFinal(data); String encryptedStr = ""; for (int i = 0; i < encrypted.length; i++) encryptedStr += (char) encrypted[i]; //decryoption Cipher d_c = Cipher.getInstance("AES"); SecretKeySpec d_keySpec = new SecretKeySpec(KEY, "AES"); d_c.init(Cipher.DECRYPT_MODE, d_keySpec, new IvParameterSpec(IV2)); byte[] decrypted = d_c.doFinal(encrypted); String decryptedStr = ""; for (int i = 0; i < decrypted.length; i++) decryptedStr += (char) decrypted[i]; Log.d("", decryptedStr); } catch (Exception ex) { Log.d("", ex.getMessage()); } } Any ideas what I'm doing wrong? How can I get 256 bit AES encryption (only change key to 32-byte long array?) Encryption is a new topic for me so please for newbie friendly answers.

    Read the article

  • Can I specify default value?

    - by atch
    Why is it that for user defined types when creating an array of objects every element of this array is initialized with default ctor but when I create built-in type this isn't the case? And second question: is it possible to specify default value to be used while initialize? Something like this (not valid): char* p = new char[size]('\0'); And another question in this topic while I'm with arrays. I suppose that when creating an array of user defined type and knowing the fact that every elem. of this array will be initialized with default value firstly why? If arrays for built in types do not initialize their elems. with their dflts why do they do it for UDT, and secondly: is there a way to switch it off/avoid/circumvent somehow? It seems like bit of a waste if I for example have created an array with size 10000 and then 10000 times dflt ctor will be invoked and I will (later on) overwrite this values anyway. I think that behaviour should be consistent, so either every type of array should be initialized or none. And I think that the behaviour for built-in arrays is more appropriate.

    Read the article

  • How to deal with Unicode strings in C/C++ in a cross-platform friendly way?

    - by Sorin Sbarnea
    On platforms different than Windows you could easily use char * strings and treat them as UTF-8. The problem is that on Windows you are required to accept and send messages using wchar* strings (W). If you'll use the ANSI functions (A) you will not support Unicode. So if you want to write truly portable application you need to compile it as Unicode on Windows. Now, In order to keep the code clean I would like to see what is the recommended way of dealing with strings, a way that minimize ugliness in the code. Type of strings you may need: std::string, std::wstring, std::tstring,char *,wchat_t *, TCHAR*, CString (ATL one). Issues you may encounter: cout/cerr/cin and their Unicode variants wcout,wcerr,wcin all renamed wide string functions and their TCHAR macros - like strcmp, wcscmp and _tcscmp. constant strings inside code, with TCHAR you will have to fill your code with _T() macros. What approach do you see as being best? (examples are welcome) Personally I would go for a std::tstring approach but I would like to see how would do to the conversions where they are necessary.

    Read the article

  • Boost Date_Time problem compiling a simple program

    - by Andry
    Hello! I'm writing a very stupid program using Boost Date_Time library. int main(int srgc, char** argv) { using namespace boost::posix_time; date d(2002,Feb,1); //an arbitrary date ptime t1(d, hours(5)+nanosec(100)); //date + time of day offset ptime t2 = t1 - minutes(4)+seconds(2); ptime now = second_clock::local_time(); //use the clock date today = now.date(); //Get the date part out of the time } Well I cannot compile it, compiler does not recognize a type... Well I used many features of Boost libs like serialization and more... I correctly built them and, looking in my /usr/local/lib folder I can see that libboost_date_time.so is there (a good sign which means I was able to build that library) When I compile I write the following: g++ -lboost_date_time main.cpp But the errors it showed me when I specify the lib are the same of those ones where I do not specify any lib. What is this? Anyone knows? The error is main.cpp: In function ‘int main(int, char**)’: main.cpp:9: error: ‘date’ was not declared in this scope main.cpp:9: error: expected ‘;’ before ‘d’ main.cpp:10: error: ‘d’ was not declared in this scope main.cpp:10: error: ‘nanosec’ was not declared in this scope main.cpp:13: error: expected ‘;’ before ‘today’

    Read the article

  • Get the character count of a textarea including newlines

    - by styfle
    I tested this code in Chrome and there seems to be a bug involving the newlines. I am reaching the maxlength before I actually use all the characters. <textarea id="myText" maxlength="200" style="width:70%;height:200px"> Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s... Enter something: </textarea> <div> Char Count <span id="count"></span>/<span id="max"></span> </div>? <script> var ta = document.getElementById('myText'); document.getElementById('max').innerHTML = ta.maxLength; setInterval(function() { document.getElementById('count').innerHTML = ta.value.length; }, 250);? </script> How can I accurately get the char count of a textarea? jsFiddle demo: http://jsfiddle.net/Qw6vz/1/

    Read the article

  • How to call a function from another class file

    - by Guy Parker
    I am very familiar with writing VB based applications but am new to Xcode (and Objective C). I have gone through numerous tutorials on the web and understand the basics and how to interact with Interface Builder etc. However, I am really struggling with some basic concepts of the C language and would be grateful for any help you can offer. Heres my problem… I have a simple iphone app which has a view controller (FirstViewController) and a subview (SecondViewController) with associated header and class files. In the FirstViewController.m have a function defined @implementation FirstViewController (void) writeToServer:(const uint8_t ) buf { [oStream write:buf maxLength:strlen((char)buf)]; } It doesn't really matter what the function is. I want to use this function in my SecondViewController, so in SecondViewController.m I import FirstViewController.h import "SecondViewController.h" import "FirstViewController.h" @implementation SecondViewController -(IBAction) SetButton: (id) sender { NSString *s = [@"Fill:" stringByAppendingString: FillLevelValue.text]; NSString *strToSend = [s stringByAppendingString: @":"]; const uint8_t *str = (uint8_t *) [strToSend cStringUsingEncoding:NSASCIIStringEncoding]; FillLevelValue.text = strToSend; [FirstViewController writeToServer:str]; } This last line is where my problem is. XCode tells me that FirstViewController may not respond to writeToServer. And when I try to run the application it crashes when this function is called. I guess I don't fully understand how to share functions and more importantly, the relationship between classes. In an ideal world I would create a global class to place my functions in and call them as required. Any advice gratefully received.

    Read the article

  • What does this structure actually do?

    - by LGTrader
    I found this structure code in a Julia Set example from a book on CUDA. I'm a newbie C programmer and cannot get my head around what it's doing, nor have I found the right thing to read on the web to clear it up. Here's the structure: struct cuComplex { float r; float i; cuComplex( float a, float b ) : r(a), i(b) {} float magnitude2( void ) { return r * r + i * i; } cuComplex operator*(const cuComplex& a) { return cuComplex(r*a.r - i*a.i, i*a.r + r*a.i); } cuComplex operator+(const cuComplex& a) { return cuComplex(r+a.r, i+a.i); } }; and it's called very simply like this: cuComplex c(-0.8, 0.156); cuComplex a(jx, jy); int i = 0; for (i=0; i<200; i++) { a = a * a + c; if (a.magnitude2() > 1000) return 0; } return 1; So, the code did what? Defined something of structure type 'cuComplex' giving the real and imaginary parts of a number. (-0.8 & 0.156) What is getting returned? (Or placed in the structure?) How do I work through the logic of the operator stuff in the struct to understand what is actually calculated and held there? I think that it's probably doing recursive calls back into the stucture float magnitude2 (void) { return return r * r + i * i; } probably calls the '*' operator for r and again for i, and then the results of those two operations call the '+' operator? Is this correct and what gets returned at each step? Just plain confused. Thanks!

    Read the article

  • Optimize a MySQL count each duplicate Query

    - by Onema
    I have the following query That gets the city name, city id, the region name, and a count of duplicate names for that record: SELECT Country_CA.City AS currentCity, Country_CA.CityID, globe_region.region_name, ( SELECT count(Country_CA.City) FROM Country_CA WHERE City LIKE currentCity ) as counter FROM Country_CA LEFT JOIN globe_region ON globe_region.region_id = Country_CA.RegionID AND globe_region.country_code = Country_CA.CountryCode ORDER BY City This example is for Canada, and the cities will be displayed on a dropdown list. There are a few towns in Canada, and in other countries, that have the same names. Therefore I want to know if there is more than one town with the same name region name will be appended to the town name. Region names are found in the globe_region table. Country_CA and globe_region look similar to this (I have changed a few things for visualization purposes) CREATE TABLE IF NOT EXISTS `Country_CA` ( `City` varchar(75) NOT NULL DEFAULT '', `RegionID` varchar(10) NOT NULL DEFAULT '', `CountryCode` varchar(10) NOT NULL DEFAULT '', `CityID` int(11) NOT NULL DEFAULT '0', PRIMARY KEY (`City`,`RegionID`), KEY `CityID` (`CityID`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; AND CREATE TABLE IF NOT EXISTS `globe_region` ( `country_code` char(2) COLLATE utf8_unicode_ci NOT NULL, `region_code` char(2) COLLATE utf8_unicode_ci NOT NULL, `region_name` varchar(50) COLLATE utf8_unicode_ci NOT NULL, PRIMARY KEY (`country_code`,`region_code`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; The query on the top does exactly what I want it to do, but It takes way too long to generate a list for 5000 records. I would like to know if there is a way to optimize the sub-query in order to obtain the same results faster. the results should look like this City CityID region_name counter sheraton 2349269 British Columbia 1 sherbrooke 2349270 Quebec 2 sherbrooke 2349271 Nova Scotia 2 shere 2349273 British Columbia 1 sherridon 2349274 Manitoba 1

    Read the article

  • C# Web Service gets stuck waiting for lock, does not return

    - by blue
    We have a C#(2.0) application which talks to our server(in java) via web services. Lately we have started seeing following behavior in (ONLY)one of our lab machines(XP): Once in a while(every few days), one of the webservice request will just get stuck, will not return or timeout. Following is the stacktrace where it seem to be stuck. Have no clue what is going on here. Any pointer would be of great help. ESP EIP 05eceeec 7c90eb94 [GCFrame: 05eceeec] 05ecefbc 7c90eb94 [HelperMethodFrame_1OBJ: 05ecefbc] System.Threading.Monitor.Enter(System.Object) 05ecf014 7a5b0034 System.Net.ConnectionGroup.Disassociate(System.Net.Connection) 05ecf040 7a5aeaa7 System.Net.Connection.PrepareCloseConnectionSocket(System.Net.ConnectionReturnResult ByRef) 05ecf0a4 7a5ac0e1 System.Net.Connection.ReadStartNextRequest(System.Net.WebRequest, System.Net.ConnectionReturnResult ByRef) 05ecf0e8 7a5b1119 System.Net.ConnectStream.CallDone(System.Net.ConnectionReturnResult) 05ecf0fc 7a5b3b5a System.Net.ConnectStream.ReadChunkedSync(Byte[], Int32, Int32) 05ecf114 7a5b2b90 System.Net.ConnectStream.ReadWithoutValidation(Byte[], Int32, Int32, Boolean) 05ecf160 7a5b29cc System.Net.ConnectStream.Read(Byte[], Int32, Int32) 05ecf1a0 79473cab System.IO.StreamReader.ReadBuffer(Char[], Int32, Int32, Boolean ByRef) 05ecf1c4 79473bd6 System.IO.StreamReader.Read(Char[], Int32, Int32) 05ecf1e8 69c29119 System.Xml.XmlTextReaderImpl.ReadData() 05ecf1f8 69c2ad70 System.Xml.XmlTextReaderImpl.ParseDocumentContent() 05ecf20c 69c292d7 System.Xml.XmlTextReaderImpl.Read() 05ecf21c 69c2929d System.Xml.XmlTextReader.Read() 05ecf220 6991b3e7 System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(System.Web.Services.Protocols.SoapClientMessage, System.Net.WebResponse, System.IO.Stream, Boolean) 05ecf268 69919ed1 System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(System.String, System.Object[])

    Read the article

  • OmniCppComplete: Completing on Class Members which are STL containers

    - by Robert S. Barnes
    Completion on class members which are STL containers is failing. Completion on local objects which are STL containers works fine. For example, given the following files: // foo.h #include <string> class foo { public: void set_str(const std::string &); std::string get_str_reverse( void ); private: std::string str; }; // foo.cpp #include "foo.h" using std::string; string foo::get_str_reverse ( void ) { string temp; temp.assign(str); reverse(temp.begin(), temp.end()); return temp; } /* ----- end of method foo::get_str ----- */ void foo::set_str ( const string &s ) { str.assign(s); } /* ----- end of method foo::set_str ----- */ I've generated the tags for these two files using: ctags -R --c++-kinds=+pl --fields=+iaS --extra=+q . When I type temp. in the cpp I get a list of string member functions as expected. But if I type str. omnicppcomplete spits out "Pattern Not Found". I've noticed that the temp. completion only works if I have the using std::string; declaration. How do I get completion to work on my class members which are STL containers?

    Read the article

  • C++ operator lookup rules / Koenig lookup

    - by John Bartholomew
    While writing a test suite, I needed to provide an implementation of operator<<(std::ostream&... for Boost unit test to use. This worked: namespace theseus { namespace core { std::ostream& operator<<(std::ostream& ss, const PixelRGB& p) { return (ss << "PixelRGB(" << (int)p.r << "," << (int)p.g << "," << (int)p.b << ")"); } }} This didn't: std::ostream& operator<<(std::ostream& ss, const theseus::core::PixelRGB& p) { return (ss << "PixelRGB(" << (int)p.r << "," << (int)p.g << "," << (int)p.b << ")"); } Apparently, the second wasn't included in the candidate matches when g++ tried to resolve the use of the operator. Why (what rule causes this)? The code calling operator<< is deep within the Boost unit test framework, but here's the test code: BOOST_AUTO_TEST_SUITE(core_image) BOOST_AUTO_TEST_CASE(test_output) { using namespace theseus::core; BOOST_TEST_MESSAGE(PixelRGB(5,5,5)); // only compiles with operator<< definition inside theseus::core std::cout << PixelRGB(5,5,5) << "\n"; // works with either definition BOOST_CHECK(true); // prevent no-assertion error } BOOST_AUTO_TEST_SUITE_END() For reference, I'm using g++ 4.4 (though for the moment I'm assuming this behaviour is standards-conformant).

    Read the article

< Previous Page | 145 146 147 148 149 150 151 152 153 154 155 156  | Next Page >