Search Results

Search found 4685 results on 188 pages for 'cpp beginner'.

Page 168/188 | < Previous Page | 164 165 166 167 168 169 170 171 172 173 174 175  | Next Page >

  • Setting the default stack size on Linux globally for the program

    - by wowus
    So I've noticed that the default stack size for threads on linux is 8MB (if I'm wrong, PLEASE correct me), and, incidentally, 1MB on Windows. This is quite bad for my application, as on a 4-core processor that means 64 MB is space is used JUST for threads! The worst part is, I'm never using more than 100kb of stack per thread (I abuse the heap a LOT ;)). My solution right now is to limit the stack size of threads. However, I have no idea how to do this portably. Just for context, I'm using Boost.Thread for my threading needs. I'm okay with a little bit of #ifdef hell, but I'd like to know how to do it easily first. Basically, I want something like this (where windows_* is linked on windows builds, and posix_* is linked under linux builds) // windows_stack_limiter.c int limit_stack_size() { // Windows impl. return 0; } // posix_stack_limiter.c int limit_stack_size() { // Linux impl. return 0; } // stack_limiter.cpp int limit_stack_size(); static volatile int placeholder = limit_stack_size(); How do I flesh out those functions? Or, alternatively, am I just doing this entirely wrong? Remember I have no control over the actual thread creation (no new params to CreateThread on Windows), as I'm using Boost.Thread.

    Read the article

  • How to avoid using the plld.exe utility in VS2008 (for linking C++ and Prolog codes)

    - by Joshua Green
    Here is my code in its entirety: Trying "listing." at the Prolog prompt that pops up when I run the program confirms that my Prolog source code has been loaded (consulted). #include <iostream> #include <fstream> #include <string> #include <math.h> #include <stdio.h> #include <stdlib.h> #include <stdafx.h> using namespace std; #include "Windows.h" #include "ctype.h" #include "SWI-cpp.h" #include "SWI-Prolog.h" #include "SWI-Stream.h" int main(int argc, char** argv) { argc = 4; argv[0] = "libpl.dll"; argv[1] = "-G32m"; argv[2] = "-L32m"; argv[3] = "-T32m"; PL_initialise(argc, argv); if ( !PL_initialise(argc, argv) ) PL_halt(1); PlCall( "consult(swi('plwin.rc'))" ); PlCall( "consult('hello.pl')" ); PL_halt( PL_toplevel() ? 0 : 1 ); } So this is how to load a Prolog source code (hello.pl) at run time into VS2008 without having to use plld at the VS command prompt.

    Read the article

  • How to develop for iphone application about "retrieving database file on web"?

    - by coverboy
    Hi...all experts! I'm a newbie to iphone developer. Well, currently, I'm developing iphone for Location Based Service. That application need to have these functions. 1. hierarchical tree-view on navigation bar. 2. list up page 3. detail page for example, Let's say. I have top category like "Restaurant, Hotel, Gift Shop" Second level "New York, LA, London,....." Third Level displays all Data with 1 photo. Fourth Level displays Detail of that "Restaurant or Hotel, Gift shop, ..." So, My Only Interest is "How to retrieve the data from remote database server. not using iphone local one." Because, that locations, and shops should be updated frequently, (you know some shops closed, new shops opens.) So, till now, I figured out that using XML to retrieve data. However, using XML is the most effective way to implement? Is there any other way to accomplish this work? You know, transferring XML data via 3G Network is really slow. XML file have more bytes than plist file. I'm currently a beginner of iphone development. So, please help me find a right way!! And, one more question, if I use xml way. Is it possible to Paging? (First page 10 lists up, below that more button...) well, you might guess each category have hundreds of shops!!

    Read the article

  • Ruby : UTF-8 IO

    - by subtenante
    I use ruby 1.8.7. I try to parse some text files containing greek sentences, encoded in UTF-8. (I can't much paste here sample files, because they are subject to copyright. Really just some greek text encoded in UTF-8.) I want, for each file, to parse the file, extract all the words, and make a list of each new word found in this file. All that saved to one big index file. Here is my code : #!/usr/bin/ruby -KU def prepare_line(l) l.gsub(/^\s*[ST]\d+\s*:\s*|\s+$|\(\d+\)\s*/u, "") end def tokenize(l) l.split /['·.;!:\s]+/u end $dict = {} $cpt = 0 $out = File.new 'out.txt', 'w' def lesson(file) $cpt = $cpt + 1 file.readlines.each do |l| $out.puts l l = prepare_line l tokenize(l).each do |t| unless $dict[t] $dict[t] = $cpt $out.puts " #{t}\n" end end end end Dir.new('etc/').each do |filename| f = File.new("etc/#{filename}") unless File.directory? f lesson f end end Here is part of my output : ?@???†?†?????????? ?...[snip very long hangul/hanzi mishmash]... ????????†? ???N2 : ?e?te?? (2) µ???µa (Note that the puts l part seems to work fine, at the end of the given output line.) Any idea what is wrong with my code ? (General comments about ruby idioms I could use are very welcome, I'm really a beginner.)

    Read the article

  • Unhandled Exception error message

    - by Joshua Green
    Does anyone know why including a term such as: t = PL_new_term_ref(); would cause an Unhandled Exception error message: 0xC0000005: Access violation reading location 0x0000000c. (Visual Studio 2008) I have a header file: class UserTaskProlog : public ArAction { public: UserTaskProlog( const char* name = " sth " ); ~UserTaskProlog( ); AREXPORT virtual ArActionDesired *fire( ArActionDesired currentDesired ); private: term_t t; }; and a cpp file: UserTaskProlog::UserTaskProlog( const char* name ) : ArAction( name, " sth " ) { char** argv; argv[ 0 ] = "libpl.dll"; PL_initialise( 1, argv ); PlCall( "consult( 'myProg.pl' )" ); } UserTaskProlog::~UserTaskProlog( ) { } ArActionDesired *UserTaskProlog::fire( ArActionDesired currentDesired ) { cout << " something " << endl; t = PL_new_term_ref( ); } Without t=PL_new_term_ref() everything works fine, but when I start adding my Prolog code (declarations first, such as t=PL_new_term_ref), I get this Access Violation error message. I'd appreciate any help. Thanks,

    Read the article

  • jQuery Checkbox Error

    - by Zack Fernandes
    Hello, I am working on a jQuery-based todo list interface, and have hit a bit of a wall. The jQuery I am working with is a bit hacked together from various tutorials I have read, as I'm a bit of a beginner. $('#todo input:checkbox').click(function(){ var id = this.attr("value"); if(!$(this).is(":checked")) { alert("Starting."); $.ajax({ type: "GET", url: "/todos/check/"+id, success: function(){ alert("It worked.") } }); } }) This is the HTML I am using, <div id="todo"> <input type="checkbox" checked="yes" value="1"> Hello, world. <br /> </div> Any help on this would be greatly appreciated. For reference, thereason I have alerts in the jQuery is for debugging. The reason I can tell the code isn't working is because I am not getting these alerts. Thanks.

    Read the article

  • Visual Studio crashes when I add a .settings file in a C++ Windows form application

    - by Ant
    I'm trying to add a .settings file in a windows form application by adding a (whatever) file in the project and have it named smthng.settings. Right after it is created, it crashes (if I look into the project's directory the file is there, but it's not "in" the project). Am I doing it wrong or could it be that the problem lies elsewhere? Edit: It seems that it's the settings designer that crashes. Partially Solved:If I add a (whatever).config file, then rename it to .settings and change it's file type to C/C++ Code (don't ask how I figured this out..) then I can add to it settings, but if I do add something that has any connection to the form then automatically a (whatever).config with thew same name spawns (which is identical to the (whatever).setting even if change one of them) and at the stdafx.cpp a #include '(whatever).h' appears, which is a problem, because there is not such a header. (if I erase it or just create a blank (whatever).h it doesn't work. Apparently I have to somehow connect all the data in the (w/e).settings to (w/e).h as well or maybe something else) Anyone had this problem before? Anyone has any ideas?

    Read the article

  • Help me to refactor this F# code to tail recursion

    - by Kev
    I write some code to learning F#. Here is a example: let nextPrime list= let rec loop n= match n with | _ when (list |> List.filter (fun x -> x <= ( n |> double |> sqrt |> int)) |> List.forall (fun x -> n % x <> 0)) -> n | _ -> loop (n+1) loop (List.max list + 1) let rec findPrimes num= match num with | 1 -> [2] | n -> let temp = findPrimes <| n-1 (nextPrime temp ) :: temp //find 10 primes findPrimes 10 |> printfn "%A" I'm very happy that it just works! I'm totally beginner to recursion Recursion is a wonderful thing. I think findPrimes is not efficient. Someone help me to refactor findPrimes to tail recursion if possible? BTW, is there some more efficient way to find first n primes?

    Read the article

  • little java help....

    - by jona
    Hi I am doing some practice problems and trying to print a diagonal line like the example below. I have writen the program you see below and I honestly dont understand what I am doing wrong. I m a java beginner and I cant see how to find the error. Example ( If you only see a straight line of stars...then imagine it diagonally....from top left to bottom right) * * * * * code: class Diagonal{ public static void main(String args[]) { int row, col; for(row = 1; row < 6; row++) { for(col = 1; col <= row; col++) { if(col==row){ System.out.print("*"); } else{ System.out.print(""); } System.out.println(); } } } } I am trying to learn for loops because they really confuse me. Another practice is to print a similar diagonal line but this time from right to left. I cant do that without getting this right however :( I believe they will be pretty similar? Above my reasining is this: As long as the column # is the same as the row number the print the line or otherwise leave a blank....what's wrong with how i did it? THANK YOU!

    Read the article

  • C++ data member initializer is not allowed

    - by user1435915
    I totally new to C++ so bear with me. I want to make a class with a static array, and access to this array from the main. Here is what i want to do in C#. namespace ConsoleApplication1 { class Program { static void Main(string[] args) { Class a = new Class(); Console.WriteLine(a.arr[1]); } } } ===================== namespace ConsoleApplication1 { class Class { public static string[] s_strHands = new string[]{"one","two","three"}; } } Here is what i have tried: // justfoolin.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include <string> #include <iostream> using namespace std; class Class { public: static string arr[3] = {"one", "two", "three"}; }; int _tmain(int argc, _TCHAR* argv[]) { Class x; cout << x.arr[2] << endl; return 0; } But i got: IntelliSense: data member initializer is not allowed

    Read the article

  • Does QThread::sleep() require the event loop to be running?

    - by suszterpatt
    I have a simple client-server program written in Qt, where processes communicate using MPI. The basic design I'm trying to implement is the following: The first process (the "server") launches a GUI (derived from QMainWindow), which listens for messages from the clients (using repeat fire QTimers and asynchronous MPI receive calls), updates the GUI depending on what messages it receives, and sends a reply to every message. Every other process (the "clients") runs in an infinite loop, and all they are intended to do is send a message to the server process, receive the reply, go to sleep for a while, then wake up and repeat. Every process instantiates a single object derived from QThread, and calls its start() method. The run() method of these classes all look like this: from foo.cpp: void Foo::run() { while (true) { // Send message to the first process // Wait for a reply // Do uninteresting stuff with the reply sleep(3); // also tried QThread::sleep(3) } } In the client's code, there is no call to exec() anywhere, so no event loop should start. The problem is that the clients never wake up from sleeping (if I surround the sleep() call with two writes to a log file, only the first one is executed, control never reaches the second). Is this because I didn't start the event loop? And if so, what is the simplest way to achieve the desired functionality?

    Read the article

  • I get this error: "glibc detected"

    - by AKGMA
    Hi I just wrote a piece of CPP code and I compiled it using G++ in ubuntu. When I run my code everything is fine, the code runs well and gives output but doesn't exit and it gives this error: *** glibc detected *** ./a.out: free(): invalid next size (fast): 0x09f931f0 *** ======= Backtrace: ========= /lib/libc.so.6(+0x6c501)[0x3de501] /lib/libc.so.6(+0x6dd70)[0x3dfd70] /lib/libc.so.6(cfree+0x6d)[0x3e2e5d] /usr/lib/libstdc++.so.6(_ZdlPv+0x21)[0x6e2441] ./a.out[0x8049ce6] /lib/libc.so.6(+0x2f69e)[0x3a169e] /lib/libc.so.6(+0x2f70f)[0x3a170f] /lib/libc.so.6(__libc_start_main+0xef)[0x388cef] ./a.out[0x8048a61] ======= Memory map: ======== 00219000-0021a000 r-xp 00000000 00:00 0 [vdso] 00354000-00370000 r-xp 00000000 08:01 8781845 /lib/ld-2.12.1.so 00370000-00371000 r--p 0001b000 08:01 8781845 /lib/ld-2.12.1.so 00371000-00372000 rw-p 0001c000 08:01 8781845 /lib/ld-2.12.1.so 00372000-004c9000 r-xp 00000000 08:01 8781869 /lib/libc-2.12.1.so 004c9000-004ca000 ---p 00157000 08:01 8781869 /lib/libc-2.12.1.so 004ca000-004cc000 r--p 00157000 08:01 8781869 /lib/libc-2.12.1.so 004cc000-004cd000 rw-p 00159000 08:01 8781869 /lib/libc-2.12.1.so 004cd000-004d0000 rw-p 00000000 00:00 0 00638000-00717000 r-xp 00000000 08:01 3935829 /usr/lib/libstdc++.so.6.0.14 00717000-0071b000 r--p 000de000 08:01 3935829 /usr/lib/libstdc++.so.6.0.14 0071b000-0071c000 rw-p 000e2000 08:01 3935829 /usr/lib/libstdc++.so.6.0.14 0071c000-00723000 rw-p 00000000 00:00 0 00909000-0092d000 r-xp 00000000 08:01 8781918 /lib/libm-2.12.1.so 0092d000-0092e000 r--p 00023000 08:01 8781918 /lib/libm-2.12.1.so 0092e000-0092f000 rw-p 00024000 08:01 8781918 /lib/libm-2.12.1.so 00fdb000-00ff5000 r-xp 00000000 08:01 8781903 /lib/libgcc_s.so.1 00ff5000-00ff6000 r--p 00019000 08:01 8781903 /lib/libgcc_s.so.1 00ff6000-00ff7000 rw-p 0001a000 08:01 8781903 /lib/libgcc_s.so.1 08048000-0804b000 r-xp 00000000 08:01 8652645 /home/akg/Desktop/contest/a.out 0804b000-0804c000 r--p 00002000 08:01 8652645 /home/akg/Desktop/contest/a.out 0804c000-0804d000 rw-p 00003000 08:01 8652645 /home/akg/Desktop/contest/a.out 09f93000-09fb4000 rw-p 00000000 00:00 0 [heap] b7600000-b7621000 rw-p 00000000 00:00 0 b7621000-b7700000 ---p 00000000 00:00 0 b7765000-b7768000 rw-p 00000000 00:00 0 b7775000-b7779000 rw-p 00000000 00:00 0 bf9a7000-bf9c8000 rw-p 00000000 00:00 0 [stack] Aborted What does this mean? How can i get rid of it? I'm not using malloc or free , I'm just using vector!

    Read the article

  • Grep expression with special file names

    - by user2919185
    i am a real beginner in csh/tcsh scripting and that's why i need your help. The problem is I have to go through some regular files in directories and find those files, that have their own name in its content. In the following piece of script is cycle in which I am going through paths and using grep to find the file's name in its content. What is surely correct is $something:q - is array of paths where i have to find files. The next variable is name in which is only name of current file. for example: /home/computer/text.txt (paths) and: text.txt (name) And my biggest problem is to find names of files in their content. It's quite difficult for me to write correct grep for this, cause the names of files and directories that i am passing through are mad. Here are some of them: /home/OS/pocitacove/testovaci_adresar/z/test4.pre_expertov/!_1 /home/OS/pocitacove/testovaci_adresar/z/test4.pre_expertov/dam/$user/:e/'/-r /home/OS/pocitacove/testovaci_adresar/z/test3/skusime/ taketo/ taketo /home/OS/pocitacove/testovaci_adresar/z/test4.pre_expertov/.-bla/.-bla/.a=b /home/OS/pocitacove/testovaci_adresar/z/test4.pre_expertov/.-bla/.-bla/@ /home/OS/pocitacove/testovaci_adresar/z/test4.pre_expertov/.-bla/.-bla/: /home/OS/pocitacove/testovaci_adresar/z/test4.pre_expertov/.-bla/.-bla/'ano' foreach paths ($something:q) set name = "$paths:t" @ number = (`grep -Ec "$name" "$paths"`) if ($number != 0) then echo -n "$paths " echo $number endif @ number = 0 end

    Read the article

  • php and mysql listing databases and looping through results

    - by Jacksta
    Beginner help needed :) I am doign an example form a php book which lists tables in databases. I am getting an error on line 36: $db_list .= "$table_list"; <?php //connect to database $connection = mysql_connect("localhost", "admin_cantsayno", "cantsayno") or die(mysql_error()); //list databases $dbs = @mysql_list_dbs($connection) or die(mysql_error()); //start first bullet list $db_list = "<ul>"; $db_num = 0; //loop through results of functions while ($db_num < mysql_num_rows($dbs)) { //get database names and make each a list point $db_names[$db_num] = mysql_tablename($dbs, $db_num); $db_list .= "<li>$db_names[$db_num]"; //get table names and make another list $tables = @mysql_list_tables($db_names[$db_num]) or die(mysql_error()); $table_list = "<ul>"; $table_num = 0; //loop through results of function while ($table_num < mysql_num_rows($tables)){ //get table names and make each bullet point $table_names[$table_num] = mysql_tablename($tables, $table_num); $table_list .= "<li>$table_names[$table_num]"; $table_num++; } //close inner bullet list and increment number to continue $table_list .= "</ul>" $db_list .= "$table_list"; $db_num++; } //close outer bullet list $db_list .= "</ul>"; ?> <html> <head> <title>MySQL Tables</title> </head> <body> <p><strong>Data bases and tables on local host</strong></p> <? echo "$db_list"; ?> </body>

    Read the article

  • How to encrypt/decrypt a file in Java?

    - by Petike
    Hello, I am writing a Java application which can "encrypt" and consequently "decrypt" whatever binary file. I am just a beginner in the "cryptography" area so I would like to write a very simple application for the beginning. For reading the original file, I would probably use the java.io.FileInputStream class to get the "array of bytes" byte originalBytes[] of the file. Then I would probably use some very simple cipher, for example "shift up every byte by 1" and then I would get the "encrypted" bytes byte encryptedBytes[] and let's say that I would also set a "password" for it, for example "123456789". Next, when somebody wants to "decrypt" that file, he has to enter the password ("123456789") first and after that the file could be decrypted (thus "shift down every byte by 1") and consequently saved to the output file via java.io.FileOutputStream I am just wondering how to "store" the password information to the encrypted file so that the decrypting application knows if the entered password and the "real" password equals? Probably it would be silly to add the password (for example the ASCII ordinal numbers of the password letters) to the beginning of the file (before the encrypted data). So my main question is how to store the password information to the encrypted file?

    Read the article

  • Want to display a 3D model on the iPhone: how to get started?

    - by JeremyReimer
    I want to display and rotate a single 3D model, preferably textured, on the iPhone. Doesn't have to zoom in and out, or have a background, or anything. I have the following: an iPhone a MacBook the iPhone SDK Blender My knowledge base: I can make 3D models in various 3D programs (I'm most comfortable with 3D Studio Max, which I once took a course on, but I've used others) General knowledge of procedural programming from years ago (QuickBasic - I'm old!) Beginner's knowledge of object-oriented programming from going through simple Java and C# tutorials (Head Start C# book and my wife's intro to OOP course that used Java) I have managed to display a 3D textured model and spin it using a tutorial in C# I got off the net (I didn't just copy and paste, I understand basically how it works) and the XNA game development library, using Visual Studio on Windows. What I do not know: Much about Objective C Anything about OpenGL or OpenGL ES, which the iPhone apparently uses Anything about XCode My main problem is that I don't know where to start! All the iPhone books I found seem to be about creating GUI applications, not OpenGL apps. I found an OpenGL book but I don't know how much, if any, applies to iPhone development. And I find the Objective C syntax somewhat confusing, with the weird nested method naming, things like "id" that don't make sense, and the scary thought that I have to do manual memory management. Where is the best place to start? I couldn't find any tutorials for this sort of thing, but maybe my Google-Fu is weak. Or maybe I should start with learning Objective C? I know of books like Aaron Hillgrass', but I've also read that they are outdated and much of the sample code doesn't work on the iPhone SDK, plus it seems geared towards the Model-View-Controller paradigm which doesn't seem that suited for 3D apps. Basically I'm confused about what my first steps should be.

    Read the article

  • Performance difference in for loop condition?

    - by CSharperWithJava
    Hello all, I have a simple question that I am posing mostly for my curiousity. What are the differences between these two lines of code? (in C++) for(int i = 0; i < N, N > 0; i++) for(int i = 0; i < N && N > 0; i++) The selection of the conditions is completely arbitrary, I'm just interested in the differences between , and &&. I'm not a beginner to coding by any means, but I've never bothered with the comma operator. Are there performance/behavior differences or is it purely aesthetic? One last note, I know there are bigger performance fish to fry than a conditional operator, but I'm just curious. Indulge me. Edit Thanks for your answers. It turns out the code that prompted this question had misused the comma operator in the way I've described. I wondered what the difference was and why it wasn't a && operator, but it was just written incorrectly. I didn't think anything was wrong with it because it worked just fine. Thanks for straightening me out.

    Read the article

  • Help me with the simplest program for "Trusted" application

    - by idazuwaika
    Hi, I hope anyone from the large community here can help me write the simplest "Trusted" program that I can expand from. I'm using Ubuntu Linux 9.04, with TPM emulator 0.60 from Mario Strasser (http://tpm-emulator.berlios.de/). I have installed the emulator and Trousers, and can successfully run programs from tpm-tools after running tpmd and tcsd daemons. I hope to start developing my application, but I have problems compiling the code below. #include <trousers/tss.h> #include <trousers/trousers.h> #include <stdio.h> TSS_HCONTEXT hContext; int main() { Tspi_Context_Create(&hContext); Tspi_Context_Close(hContext); return 0; } After trying to compile with g++ tpm.cpp -o tpmexe I receive errors undefined reference to 'Tspi_Context_Create' undefined reference to 'Tspi_Context_Close' What do I have to #include to successfully compile this? Is there anything that I miss? I'm familiar with C, but not exactly so with Linux/Unix programming environment. ps: I am a part time student in Master in Information Security programme. My involvement with programming has been largely for academic purposes.

    Read the article

  • Which Stroustrup book should I use?

    - by Chris Simmons
    I'm a C# programmer that is looking to branch out. I'm bored of writing business software and want to start getting into graphics programming and games/simulators. So I figured, although writing that stuff isn't impossible in managed code, the "right" way to do that would be to look to C++, of course focussing on the language first, then getting into OpenGL or DirectX (or whatever). Way way back ('98? '99?) I had tried and failed to really grasp Stroustrup's The C++ Programming Language. I know that this book is often not recommended for the beginner. Anyway, I picked it back up (in a much more recent printing) and I'm actually getting it and enjoying it. I also have a copy of his textbook, Programming: Principles and Practice Using C++, which, as I understand it, is really geared toward teaching programming, not necessarily C++. I'm certainly not arrogant enough to claim I don't have anything more to learn about programming, data structures, algoriths, etc., however I'm not a novice there either. So my question is, with the goal of gaining the broader and more real-world-useful understanding of C++ and given my background, on which should I focus? The denser (as I perceive it) TCPPPL or the gentler Programming? EDIT: I thank everyone for the responses. However, I've got a personal choice here to make between these two books. Granted there are other very good books out there, but I'm already a good length into both of the books I mention and I'd like to finish one. So, can anyone respond on which would be the better and why? Time is not an issue; I'm not looking (at this point) at an "accelerated" read.

    Read the article

  • Interchange structured data between Haskell and C

    - by Eonil
    First, I'm a Haskell beginner. I'm planning integrating Haskell into C for realtime game. Haskell does logic, C does rendering. To do this, I have to pass huge complexly structured data (game state) from/to each other for each tick (at least 30 times per second). So the passing data should be lightweight. This state data may laid on sequential space on memory. Both of Haskell and C parts should access every area of the states freely. In best case, the cost of passing data can be copying a pointer to a memory. In worst case, copying whole data with conversion. I'm reading Haskell's FFI(http://www.haskell.org/haskellwiki/FFICookBook#Working_with_structs) The Haskell code look specifying memory layout explicitly. I have a few questions. Can Haskell specify memory layout explicitly? (to be matched exactly with C struct) Is this real memory layout? Or any kind of conversion required? (performance penalty) If Q#2 is true, Any performance penalty when the memory layout specified explicitly? What's the syntax #{alignment foo}? Where can I find the document about this? If I want to pass huge data with best performance, how should I do that? *PS Explicit memory layout feature which I said is just C#'s [StructLayout] attribute. Which is specifying in-memory position and size explicitly. http://www.developerfusion.com/article/84519/mastering-structs-in-c/ I'm not sure Haskell has matching linguistic construct matching with fields of C struct.

    Read the article

  • Factorial in Prolog and C++

    - by Joshua Green
    I would like to work out a number's factorial. My factorial rule is in a Prolog file and I am connecting it to a C++ code. Can someone tell me what is wrong with my C++ interface please? % factorial.pl factorial( 1, 1 ):- !. factorial( X, Fac ):- X > 1, Y is X - 1, factorial( Y, New_Fac ), Fac is X * New_Fac. // factorial.cpp # headerfiles term_t t1; term_t t2; term_t goal_term; functor_t goal_functor; int main( int argc, char** argv ) { argc = 4; argv[0] = "libpl.dll"; argv[1] = "-G32m"; argv[2] = "-L32m"; argv[3] = "-T32m"; PL_initialise(argc, argv); if ( !PL_initialise(argc, argv) ) PL_halt(1); PlCall( "consult(swi('plwin.rc'))" ); PlCall( "consult('factorial.pl')" ); cout << "Enter your factorial number: "; long n; cin >> n; PL_put_integer( t1, n ); t1 = PL_new_term_ref(); t2 = PL_new_term_ref(); goal_term = PL_new_term_ref(); goal_functor = PL_new_functor( PL_new_atom("factorial"), 2 ); PL_put_atom( t1, t2 ); PL_cons_functor( goal_term, goal_functor, t1, t2 ); PL_halt( PL_toplevel() ? 0 : 1 ); }

    Read the article

  • C++: best way to implement globally scoped data

    - by bobobobo
    I'd like to make program-wide data in a C++ program, without running into pesky LNK2005 errors when all the source files #includes this "global variable repository" file. I have 2 ways to do it in C++, and I'm asking which way is better. The easiest way to do it in C# is just public static members. C#: public static class DataContainer { public static Object data1 ; public static Object data2 ; } In C++ you can do the same thing C++ global data way#1: class DataContainer { public: static Object data1 ; static Object data2 ; } ; Object DataContainer::data1 ; Object DataContainer::data2 ; However there's also extern C++ global data way #2: class DataContainer { public: Object data1 ; Object data2 ; } ; extern DataContainer * dataContainer ; // instantiate in .cpp file In C++ which is better, or possibly another way which I haven't thought about? The solution has to not cause LNK2005 "object already defined" errors.

    Read the article

  • Duplicate Symbol Linker Error (C++ help)

    - by Vash265
    Hi. I'm learning some CSP (constraint satisfaction) theory stuff right now, and am using this library to parse XML files. I'm using Xcode as an IDE. My program compiles fine, but when it goes to link the files, I get a duplicate symbol error with the XMLParser_libxml2.hh file. My files are separated as such: A class header file that includes the XMLParser file above A class implementation file that include the class header file A main file that includes the class header file The duplicate symbol is occurring in main.o and classfile.o, but as far as I can tell, I'm not actually adding that .hh file twice. Full error: ld: duplicate symbol bool CSPXMLParser::UTF8String::to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >(std::basic_string<char, std::char_traits<char>, std::allocator<char> >&) constin /Users/vash265/CSP/Untitled/build/Untitled.build/Debug/Untitled.build/Objects-normal/x86_64/dStructFill.o and /Users/vash265/CSP/Untitled/build/Untitled.build/Debug/Untitled.build/Objects-normal/x86_64/main.o Copying the implementation of the class into the main file and taking the class implementation file out of the compilation target alleviates the error, but it's a disorganized mess this way, and I'll be adding more classes very soon (and it would be nice to have them in separate files). As I've come to understand it, this is caused by the file (XMLParser_libxml2.hh) having both the class and function definition and implementation in one file (and it seems as though this might have been necessary due to the use of templates in that 'header' file). Any ideas on how to get around sticking all my class files in my main.cpp? (I've tried ifdefs, they don't work).

    Read the article

  • Where to master HTML, CSS ans Javascript?

    - by Shahensha
    I got interested in web-development lately. I am still a student. I learnt basics of HTML, CSS and JavaScript! Then I thought I should improve my server side scripting. So I am learning Struts2 and I am doing better there. Now I have decided I should finally put my skill to some use. So I and my friend have decided to come up with a fun website for our class. But now I am realizing that, though I know server-side scripting to a good extent (not great, just good considering I am a beginner), I am nowhere near good in the basic elements viz. HTML, CSS and JavaScript! I mean, I can't do cool stuff with it. I am aware of w3schools, but it would be great if you can point out a more intuitive place where I can learn to do all the cool stuff in a short time. Some of the problems I am facing are: 1) How should I design the basic layout of my website? 2) How can I use 3rd party APIs like that of Facebook graph? regards shahensha

    Read the article

  • Combining the jquery Calendar picker with the jquery validation and getting them to play nice?

    - by MBonig
    I'm just starting to get into jquery/javascript programming so this may be a beginner question but I sure can't seem to find anything about it. I have a text field on a form. I've used the JQuery UI Calendar picker to make data entry better. I've also added jquery validation to ensure that if the user enters the date by hand that it's still valid. Here is the html: <input class="datepicker" id="Log_ServiceStartTime_date" name="Log_ServiceStartTime_date" type="text" value="3/16/2010"></input> and javascript: $('form').validate(); $('#Log_ServiceStartTime_date').rules('add','required'); $('#Log_ServiceStartTime_date').rules('add','date'); the problem I'm having is this: If a user puts in a bad date, or no date at all, the validation correctly kicks in and the error description displays. However, if the user clicks on the textbox to bring up the calendar picker and selects a date, the date fills into the field but the validation does not go away. If the user clicks into the textbox and then back out, the validation correctly goes away. How can I get the calendar picker to kick off the validation routine once a date is selected? thanks

    Read the article

< Previous Page | 164 165 166 167 168 169 170 171 172 173 174 175  | Next Page >