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  • C Structure Pointer Problem

    - by Halo
    I have this struct; #define BUFSIZE 10 struct shared_data { pthread_mutex_t th_mutex_queue; int count; int data_buffer_allocation[BUFSIZE]; int data_buffers[BUFSIZE][100]; }; and I want to allocate one of the data_buffers for a process, for that purpose I execute the following function; int allocate_data_buffer(int pid) { int i; for (i = 0; i < BUFSIZE; i++) { if (sdata_ptr->data_buffer_allocation[i] == NULL) { sdata_ptr->data_buffer_allocation[i] = pid; return i; } } return -1; } but the compiler warns me that I'm comparing pointer to a value. When I put a & in front of sdata_ptr it calms down but I'm not sure if it will work. Isn't what I wrote above supposed to be true?

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  • ASP.NET 2.0 in Virtual Trying to Use SQL State Server

    - by user251660
    We have IIS 6 running on a W2003 Server. The root web site is running a v1.1 site. Under this site we have a virtual running a v2.0 site (with a separate application pool). The web.config for the root site is using SQL as its state server and has a 1.1 SQL state server database installed. The 2.0 virtual web.config does not need state and its web.config has no reference to a state server. When we attempt to call the virtual we receive this error message. "Unable to use SQL Server because ASP.NET version 2.0 Session State is not installed on the SQL server. Please install ASP.NET Session State SQL Server version 2.0 or above. This issue is currently only occurring on one web server. The rest are able to run the 2.0 virtual application. I also notice that if we call the 2.0 virtual with the IP address it does not generate the error, however if we call it with the host header name it generates the error (this behavior is only on the 1 web server with the error, all the others can be called with either the ip or host header without error). As an additional note the root and virtual are running with SSL. My theory is that the virtual 2.0 application is inheriting the 1.1 web.config state server entry from the root and when it looks at the state server it sees it as a 1.1 version and reports the error that it needs a 2.0 state server. I however cannot understand why the other servers are not behaving in this matter. All of the servers are on the same OS service pack as well as the same version of .net framework. Any ideas? Thanks

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  • Avoiding repeated subqueries when 'WITH' is unavailable

    - by EloquentGeek
    MySQL v5.0.58. Tables, with foreign key constraints etc and other non-relevant details omitted for brevity: CREATE TABLE `fixture` ( `id` int(11) NOT NULL auto_increment, `competition_id` int(11) NOT NULL, `name` varchar(50) NOT NULL, `scheduled` datetime default NULL, `played` datetime default NULL, PRIMARY KEY (`id`) ); CREATE TABLE `result` ( `id` int(11) NOT NULL auto_increment, `fixture_id` int(11) NOT NULL, `team_id` int(11) NOT NULL, `score` int(11) NOT NULL, `place` int(11) NOT NULL, PRIMARY KEY (`id`) ); CREATE TABLE `team` ( `id` int(11) NOT NULL auto_increment, `name` varchar(50) NOT NULL, PRIMARY KEY (`id`) ); Where: A draw will set result.place to 0 result.place will otherwise contain an integer representing first place, second place, and so on The task is to return a string describing the most recently played result in a given competition for a given team. The format should be "def Team X,Team Y" if the given team was victorious, "lost to Team X" if the given team lost, and "drew with Team X" if there was a draw. And yes, in theory there could be more than two teams per fixture (though 1 v 1 will be the most common case). This works, but feels really inefficient: SELECT CONCAT( (SELECT CASE `result`.`place` WHEN 0 THEN "drew with" WHEN 1 THEN "def" ELSE "lost to" END FROM `result` WHERE `result`.`fixture_id` = (SELECT `fixture`.`id` FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` WHERE `fixture`.`competition_id` = 2 AND `result`.`team_id` = 1 ORDER BY `fixture`.`played` DESC LIMIT 1) AND `result`.`team_id` = 1), ' ', (SELECT GROUP_CONCAT(`team`.`name`) FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` LEFT JOIN `team` ON `result`.`team_id` = `team`.`id` WHERE `fixture`.`id` = (SELECT `fixture`.`id` FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` WHERE `fixture`.`competition_id` = 2 AND `result`.`team_id` = 1 ORDER BY `fixture`.`played` DESC LIMIT 1) AND `team`.`id` != 1) ) Have I missed something really obvious, or should I simply not try to do this in one query? Or does the current difficulty reflect a poor table design?

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  • What is the explanation of this results in Java ?

    - by M.H
    I have the following code : public class Main { private int i = j; //1 private int j = 10; public static void main(String[] args) { System.out.println((new Main()).i); } } and there is a compiler error in line 1 because an illegal forward reference. But when I am trying the following code : public class Main { int i = getJ(); //1 int getJ(){ return j; } int j=10; public static void main(String[] args) { System.out.println(new Main().i); } } it works fine and the result is 0.Why there is no illegal forward reference in line 1 here?.The two codes look similar to me.

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  • Pointer to a C++ class member function as a global function's parameter?

    - by marcin1400
    I have got a problem with calling a global function, which takes a pointer to a function as a parameter. Here is the declaration of the global function: int lmdif ( minpack_func_mn fcn, void *p, int m, int n, double *x, double *fvec, double ftol) The "minpack_func_mn" symbol is a typedef for a pointer to a function, defined as: typedef int (*minpack_func_mn)(void *p, int m, int n, const double *x, double *fvec, int iflag ); I want to call the "lmdif" function with a pointer to a function which is a member of a class I created, and here is the declaration of this class function: int LT_Calibrator::fcn(void *p, int m, int n, const double *x, double *fvec,int iflag) I am calling a global function like this: info=lmdif(&LT_Calibrator::fcn, 0, m, n, x, fvec, ftol) Unfortunately, I get a compiler error, which says: "error C2664: 'lmdif' : cannot convert parameter 1 from 'int (__thiscall LT_Calibrator::* )(void *,int,int,const double *,double *,int)' to 'minpack_func_mn' 1 There is no context in which this conversion is possible" Is there any way to solve that problem?

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  • floats in NSArray

    - by JordanC
    I have an NSArray of floats which I did by encapsulating the floats using [NSNumber numberWithFloat:myFloat] ; Then I passed that array somewhere else and I need to pull those floats out of the array and perform basic arithmatic. When I try [myArray objectAtIndex:i] ; The compiler complains that I'm trying to perform arithmatic on a type id. It also won't let me cast to float or double. Any ideas? This seems like it should be an easy problem. Maybe it will come to me after another cup of coffee, but some help would be appreciated. Thanks.

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  • can bind successfully to the ldap server, but needs to know how to find user w/i AD

    - by Brad
    I create a login form to bind to the ldap server, if successful, it creates a session (which the user's username is stored within), then I go to another page that has session_start(); and it works fine. What I want to do now, is add code to test if that user is a member of a specific group. So in theory, this is what I want to do if(username session is valid) { search ldap for user -> get list of groups user is member of foreach(group they are member of) { switch(group) { case STAFF: print 'they are member of staff group'; $access = true; break; default: print 'not a member of STAFF group'; $access = false; break; } if(group == STAFF) { break; } } if($access == TRUE) { // you have access to the content on this page } else { // you do not have access to this page } } How do I do a ldap_search w/o binding? I don't want to keep asking for their password on each page, and I can't pass their password thru a session. Any help is appreciated.

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  • What is wrong with this Fortran '77 snippet?

    - by notJim
    I've been tasked with maintaing some legacy fortran code, and I'm having trouble getting it to compile with gfortran. I've written a fair amount of Fortran 95, but this is my first experience with Fortran 77. This snippet of code is the problematic one: CHARACTER*22 IFILE, OFILE IFILE='TEST.IN' OFILE='TEST.OUT' OPEN(5,FILE=IFILE,STATUS='NEW') OPEN(6,FILE=OFILE,STATUS='NEW') common/pabcde/nfghi When I compile with gfortran file.FOR, all lines starting with the common statement are errors (e.g. Error: Unexpected COMMON statement at (1) for each following line until it hits the 25 error limit). I compiled with -Wall -pedantic, but fixing the warnings did not fix this problem. The crazy thing is that if I comment out all 4 lines starting with IF='TEST.IN', the program compiles and works as expected, but I must comment out all of them. Leaving any of them uncommented gives me the same errors starting with the common statement. If I comment out the common statement, I get the same errors, just starting on the following line. I am on OS X Leopard (not Snow Leopard) using gfortran. I've used this very system with gfortran extensively to write Fortran 95 programs, so in theory the compiler itself is sane. What the hell is going on with this code?

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  • How do I become better in math, after being a programmer for several years.

    - by loxs
    I've had quite a weird career till now. First I graduated from a medical school. Then I went into marketing (pharmaceuticals). And then umm, after some time, I decided to go for my (till then) hobby and became a "professional" programmer. I've been quite successful at this ever since. I have quite some languages "under my belt". I earn not bad and I have been involved in the opensource community quite heavily. The thing is that I suck at math :). Well, not totally of course, as I get my work done. But I don't know how much I suck. And I don't know how to find out. Math has never really been of any priority during my middle/high school years. I only picked as little as I could afford, because I was always getting ready to go for Medicine. Of course I know the basics of algebra. Things like "normal" and square equations. Also the basics of geometry. But well, there are things that I have missed. And lately I am being fascinated by things like probability theory, infinity, chaos/order etc. But every time I try to learn something about these topics, I hit a wall of terminology, special symbols, and some special kind of thinking, that is quite like mine (a programmer), but also a lot different (and appears weird to me). So, what kinds of books would you recommend me? It's very hard to find something suitable. All that I find are either too easy (and boring) or totally impenetrable.

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  • My Delphi 7 application halts on Application.Initialize and does not return to next line

    - by m-abdi
    I have created an application on Delphi 7. my app had running fine since yesterday. I don't know what's happened yesterday which cause my application halts on Application.Initialize line in source code and does not return to next line when i trace the program. I can't run the created executable file from widows niether while the generated file does run on another machine correctly. here is the code where the compiler stops on it: program Info_Kiosk; uses SysUtils, Forms, ... (some other units) ; {$R *.res} begin Application.Initialize; Application.CreateForm(Tfrm_Main, frm_Main); any help would be appreciated

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  • C++: namespace conflict between extern "C" and class member

    - by plaisthos
    Hi, I stumbled upon a rather exotic c++ namespace problem: condensed example: extern "C" { void solve(lprec * lp); } class A { public: lprec * lp; void solve(int foo); } void A::solve(int foo) { solve(lp); } I want to call the c function solve in my C++ member function A::solve. The compiler is not happy with my intent: error C2664: 'lp_solve_ilp::solve' : cannot convert parameter 1 from 'lprec *' to 'int' Is there something I can prefix the solve function with? C::solve does not work

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  • Why size_t arguments in template declaration need to be const?

    - by ArunSaha
    I can have std::bitset< 10 > bitsetA; or const size_t LengthB = 20; std::bitset< LengthB > bitsetB; without any problem. But, if the length is not const size_t LengthC = 30; std::bitset< LengthC > bitsetC; // Line 30, say I face the following compilation error 'LengthC' cannot appear in a constant-expression template argument 1 is invalid What is the reason for that? What would be the problem, for compiler and for user code, if line 30 was to be accepted? Is it because LengthC might have some alias?

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  • C/C++: Scanning a TIFF file using LIBTIFF

    - by Matt07
    My problem is to scan a tiff image in C and get all the pixel value (let's say for saving them in a txt file) in C/C++. I scanned the web and i found a library named "TIFFLIB" that should do what i was looking for. I downloaded it using the ubuntu package manager, but the gcc doesn't recognize the library. How do i link the library to the compiler? Have I installed it correctly? Is there any better/easier way to do that?

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  • Dimension Reduction in Categorical Data with missing values

    - by user227290
    I have a regression model in which the dependent variable is continuous but ninety percent of the independent variables are categorical(both ordered and unordered) and around thirty percent of the records have missing values(to make matters worse they are missing randomly without any pattern, that is, more that forty five percent of the data hava at least one missing value). There is no a priori theory to choose the specification of the model so one of the key tasks is dimension reduction before running the regression. While I am aware of several methods for dimension reduction for continuous variables I am not aware of a similar statical literature for categorical data (except, perhaps, as a part of correspondence analysis which is basically a variation of principal component analysis on frequency table). Let me also add that the dataset is of moderate size 500000 observations with 200 variables. I have two questions. Is there a good statistical reference out there for dimension reduction for categorical data along with robust imputation (I think the first issue is imputation and then dimension reduction)? This is linked to implementation of above problem. I have used R extensively earlier and tend to use transcan and impute function heavily for continuous variables and use a variation of tree method to impute categorical values. I have a working knowledge of Python so if something is nice out there for this purpose then I will use it. Any implementation pointers in python or R will be of great help. Thank you.

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  • dropdown list selected index changed

    - by KareemSaad
    I did my drop down list that get it,s values from database and when run the application it didnot work and compiler didnot see the code onselectedindexchanged="DDlProductFamily_SelectedIndexChanged" protected void DDlProductFamily_SelectedIndexChanged(object sender, EventArgs e) { using (SqlConnection Con = Connection.GetConnection()) { SqlCommand Com = new SqlCommand("SelectThumbByProductFamily", Con); Com.CommandType = CommandType.StoredProcedure; Com.Parameters.Add(Parameter.NewInt("@ProductCategory_Id", DDlProductFamily.SelectedValue.ToString())); SqlDataAdapter DA = new SqlDataAdapter(Com); DA.Fill(dt); DataList1.DataSource = dt; DataList1.DataBind(); } }

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  • Using typedefs (or #defines) on built in types - any sensible reason?

    - by jb
    Well I'm doing some Java - C integration, and throught C library werid type mappings are used (theres more of them;)): #define CHAR char /* 8 bit signed int */ #define SHORT short /* 16 bit signed int */ #define INT int /* "natural" length signed int */ #define LONG long /* 32 bit signed int */ typedef unsigned char BYTE; /* 8 bit unsigned int */ typedef unsigned char UCHAR; /* 8 bit unsigned int */ typedef unsigned short USHORT; /* 16 bit unsigned int */ typedef unsigned int UINT; /* "natural" length unsigned int*/ Is there any legitimate reason not to use them? It's not like char is going to be redefined anytime soon. I can think of: Writing platform/compiler portable code (size of type is underspecified in C/C++) Saving space and time on embedded systems - if you loop over array shorter than 255 on 8bit microprocessor writing: for(uint8_t ii = 0; ii < len; ii++) will give meaureable speedup.

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  • How to use #ifdef entities as part of functions in header files

    - by Crazyjavahacking
    I would like to ask if it is possible to use the entities defined in #ifdef block in header files. To be clear, I have following code: #ifdef #include <winsock2.h> #define SOCKET_HANDLE SOCKET #define CONNECTION_HANDLE SOCKET #endif SOCKET_HANDLE createServerSocket(const char* hostAddress, short port); I am Java developer and this seems completely fine for me. However compiler has a problem with this. Can you explain why is that code a problem? Also how can I force to compile it. (The idea is to have generic interface and conditional compilation to determine real types according to running platform at compile time.) Thanks

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  • Injecting a dependancy into a base class

    - by Jamie Dixon
    Hey everyone, I'm on a roll today with questions. I'm starting out with Dependency Injection and am having some trouble injecting a dependency into a base class. I have a BaseController controller which my other controllers inherit from. Inside of this base controller I do a number of checks such as determining if the user has the right privileges to view the current page, checking for the existence of some session variables etc. I have a dependency inside of this base controller that I'd like to inject using Ninject however when I set this up as I would for my other dependencies I'm told by the compiler that: Error 1 'MyProject.Controllers.BaseController' does not contain a constructor that takes 0 argument This makes sense but I'm just not sure how to inject this dependency. Should I be using this pattern of using a base controller at all or should I be doing this in a more efficient/correct way?

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  • Can Haskell's monads be thought of as using and returning a hidden state parameter?

    - by AJM
    I don't understand the exact algebra and theory behind Haskell's monads. However, when I think about functional programming in general I get the impression that state would be modelled by taking an initial state and generating a copy of it to represent the next state. This is like when one list is appended to another; neither list gets modified, but a third list is created and returned. Is it therefore valid to think of monadic operations as implicitly taking an initial state object as a parameter and implicitly returning a final state object? These state objects would be hidden so that the programmer doesn't have to worry about them and to control how they gets accessed. So, the programmer would not try to copy the object representing the IO stream as it was ten minutes ago. In other words, if we have this code: main = do putStrLn "Enter your name:" name <- getLine putStrLn ( "Hello " ++ name ) ...is it OK to think of the IO monad and the "do" syntax as representing this style of code? putStrLn :: IOState -> String -> IOState getLine :: IOState -> (IOState, String) main :: IOState -> IOState -- main returns an IOState we can call "state3" main state0 = putStrLn state2 ("Hello " ++ name) where (state2, name) = getLine state1 state1 = putStrLn state0 "Enter your name:"

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  • What features of Scala cannot be translated to Java?

    - by Paul
    The Scala compiler compiles direct to Java byte code (or .NET CIL). Some of the features of Scala could be re-done in Java straightforwardly (e.g. simple for comprehensions, classes, translating anonymous/inner functionc etc). What are the features that cannot be translated that way? That is presumably mostly of academic interest. More usefully, perhaps, what are the key features or idioms of Scala that YOU use that cannot be easily represented in Java? Are there any the other way about? Things that can be done straightforwardly in Java that have no straightforward equivalent in Scala? Idioms in Java that don't translate?

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  • Problem with basic program using Boost Threads in c++

    - by Eternal Learner
    I have a simple program which creates and executes as thread using boost threads in c++. #include<boost/thread/thread.hpp> #include<iostream> void hello() { std::cout<<"Hello, i am a thread"<<std::endl; } int main() { boost::thread th1(&hello); th1.join(); } The compiler throws an error against the th1.join() line. It says " Multiple markers at this line - undefined reference to `boost::thread::join()' - undefined reference to `boost::thread::~thread()' "

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  • An easy way to replace fread()'s with reading from a byte array?

    - by Sam Washburn
    I have a piece of code that needs to be run from a restricted environment that doesn't allow stdio (Flash's Alchemy compiler). The code uses standard fopen/fread functions and I need to convert it to read from a char* array. Any ideas on how to best approach this? Does a wrapper exist or some library that would help? Thanks! EDIT: I should also mention that it's reading in structs. Like this: fread(&myStruct, 1, sizeof(myStruct), f);

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  • How do I resolve this scope issue in VB .NET?

    - by froadie
    I have a code structure something like this: For row = 1 To numRows Dim arrayIndex As Integer = 0 For column As Integer = bucketStartColumn To bucketEndColumn ' whatever code arrayIndex = arrayIndex + 1 Next Next Dim arrayIndex As Integer = 0 For column As Integer = bucketStartColumn To bucketEndColumn ' whatever code arrayIndex = arrayIndex + 1 Next Not exactly the code, so I don't really need suggestions about refactoring, but my problem is this - with this code I get a compiler error for the first Dim arrayIndex As Integer = 0 - "Variable 'arrayIndex' hides a variable in an enclosing block." As far as I can tell, arrayIndex is local to the first for loop and shouldn't exist by the time we reach the second loop. If I try to change the second declaration of arrayIndex to arrayIndex = 0, I get the error "Name 'arrayIndex' is not declared", as I expected. So is it visible, or not? Does this have something to do with the Dim keyword? Any suggestions of how to get around this, other than naming the second index variable something else?

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  • c++ when to put method out side the class

    - by user63898
    i saw that some times in c++ applications using only namespace declarations with header and source file like this : #ifndef _UT_ #define _UT_ #include <string> #include <windows.h> namespace UT { void setRootPath(char* program_path, char* file_path); char * ConvertStringToCharP(std::string str); }; #endif //and then in UT.cpp #include "UT.h" namespace UT { char * ConvertStringToCharP(std::string str) { char * writable = new char[str.size() + 1]; std::copy(str.begin(), str.end(), writable); writable[str.size()] = '\0'; return writable; } void setRootPath(char* program_path, char* file_path) { //... } } is it better then defining classic class with static methods? or just simple class ? dose this method has something better for the compiler linker ? the methods in this namespace are called allot of times .

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  • When will YOU adopt C++0x?

    - by HighCommander4
    I'm particularly looking for input from managers of ongoing C++ projects: Have you already adopted C++0x? If so, what has your experience been like? If you haven't adopted C++0x yet, are you planning to? If so, what is your timeline (in rough terms)? Are there any obstacles that are holding you back from adopting C++0x? Perhaps you are waiting for your favourite compiler or IDE to catch up? For managers of open source projects: are you afraid that adopting C++0x will mean less developers who are willing/able to contribute because they don't know the new features? Or, on the other hand, do you think most developers have been eagerly awaiting C++0x, and and will jump at the opportunity to use it? Do you think C++0x is stable enough to be adopted by a large project?

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