Search Results

Search found 5819 results on 233 pages for 'compiler theory'.

Page 160/233 | < Previous Page | 156 157 158 159 160 161 162 163 164 165 166 167  | Next Page >

• VS2010's "Public Property <PropertyName> As <DataType> vs. Public var

  - by Velika2

  In VS2008, I used to type Public Property <PropName> As <dataType> and hit the Enter key and the IDE editor would automatically expand it out to a full blown property block. Now, from what I understand, a new feature of 2010 is that the compiler automatically "expands" the short syntax above into the same IL code that you would get with the full property GET AND SET sub methods that were are accustomed to seeing before in the editor. But functionality, how the heck is this any different than just having a Public class level variable? If the only diff is what it compiles to and if otehrwise there is no functional difference, isn't the new way less efficient than the old since it involves more code than just having a class level memory variable? Public as I thought that if you weren't going to have code behind your properties that they were essentially the same. I guess the diffrenece is that they just added the keyword "Property" but functionality, their is no diff, eh?

  Read the article

• Are returned locals automatically xvalues

  - by mark

  Following on from a comment I made on this: passing std::vector to constructor and move semantics Is the std::move necessary in the following code, to ensure that the returned value is a xvalue? std::vector<string> buildVector() { std::vector<string> local; // .... build a vector return std::move(local); } It is my understanding that this is required. I have often seen this used when returning a std::unique_ptr from a function, however GManNickG made the following comment: It is my understanding that in a return statement all local variables are automatically xvalues (expiring values) and will be moved, but I'm unsure if that only applies to the returned object itself. So OP should go ahead and put that in there until I'm more confident it shouldn't have to be. :) Can anyone clarify if the std::move is necessary? Is the behaviour compiler dependent?

  Read the article

• How can I find a package?

  - by Roman

  In my code I have the following statement import com.apple.dnssd.*; and compiler (javac) complains about this line. It writes that the package does not exist. But I think that it could be that "javac" search the package in a wrong place (directory). In this respect I have two questions: How can I know where javac search for the packages? I think that it is very likely that I have the above mentioned package but I do not know where it is located. What are the typical place to look for the packages?

  Read the article

• Webforms vs. MVC. Once you start using MVC.. Do you ever go back to webforms?

  - by punkouter

  I checked out MVC months ago and didn't really get it.. but recently as I have become a better programmer I think it is making sense.. Here is my theory.. tell me if I got it Right In the 90s for Microsoft Devs we had Classic ASP. This mixed VBscript and HTML on the same page. So you needed to create all the HTML yourself and mix HTML and VBScript. This was not considered Ideal. Then .NET came along and everyone liked it because it was similiar to event driven VB 6 style programming. It created this abstraction of binding data to ASP Servier controls. It made getting Enumerated data easy to get on the screen with one line. Then recently Jquery and SOA concepts are mixed together.. Now people think.. Why create this extra layer of abstraction when I can just directly use .NET as a data provider and use jquery AJAX calls to get the data and create the HTML with it directly .. no need for the Webforms abstraction layer.. Sowe are back to creating HTML directly like we did in 1999. So MVC is all about saying Stop pretending like WEb programming is a VB6 app! Generate HTML directly! Am I missing anything? So I wonder.. for you people out there using MVC... is it the sort of things that once you get used to it you never want to go back to webforms??

  Read the article

• Should non-English member names be changed to English?

  - by M.A. Hanin

  Situation: Automatically generated memebers, such as MenuStrip items, have their (automatically generated) names based on the text entered when the item was created. My most common situation is creating a menu-strip and adding menu-items by entering their text (using the graphical designer). Since my GUI is in Hebrew, all these members have a name which contains a Hebrew string. Something like "(hebrew-text)ToolStripItem". When I create event handlers, the event handlers "inherit" the hebrew text: "(hebrew-text)ToolStripMenuItem_Click". This actually works well, IntelliSense has no problem with Hebrew text, and so does the compiler. The question is: should I change these names (or prevent them from being created in the first place)? What are the possible consequences of keeping those names?

  Read the article

• SubSonic 3.0 - Save method with all columns as parameters?

  - by Todd Menier

  Hi, Just getting started with SubSonic. I'm using the Repository pattern, so my domain objects are totally seperate, and SubSonic-generated classes are used only in my data access layer. I'm wondering if a template exists that will give me a Save method (Insert/Update) that requires all table column values as parameters. My thinking is that since I need to do the mapping work manually, at least if my database schema changes (ie, a new column is added), I won't forget to add a corresponding mapping, since the auto-generated method signature would change and the compiler would catch it. I've considered messing with the T4 templates to add this feature, but thought I'd check if this already exists somewhere before I head down that path. Thanks in advance.

  Read the article

• Dependency Injection with @Inject in Weld (JSR-299 RI). How is the corresponding @Produces found?

  - by Thorbjørn Ravn Andersen

  I have played with the JSR-299 Reference Implementation "Weld" with the purpose of using it in a stand-alone application, and I have had a look at the documentation, and marveled at the magic. My question is how the producer of a given object to be @Inject'ed is found? Either the java compiler produces hints for annotations which is easily found by the classloader, or the complete classpath must be traversed loading all classes to see what they do which sounds highly inefficient to me, or it is a completely different approach. What is the trick?

  Read the article

• About enumerations in Delphi and c++ in 64-bit environments

  - by sum1stolemyname

  I recently had to work around the different default sizes used for enumerations in Delphi and c++ since i have to use a c++ dll from a delphi application. On function call returns an array of structs (or records in delphi), the first element of which is an enum. To make this work, I use packed records (or aligned(1)-structs). However, since delphi selects the size of an enum-variable dynamically by default and uses the smallest datatype possible (it was a byte in my case), but C++ uses an int for enums, my data was not interpreted correctly. Delphi offers a compiler switch to work around this, so the declaration of the enum becomes {$Z4} TTypeofLight = ( V3d_AMBIENT, V3d_DIRECTIONAL, V3d_POSITIONAL, V3d_SPOT ); {$Z1} My Questions are: What will become of my structs when they are compiled on/for a 64-bit environment? Does the default c++ integer grow to 8 Bytes? Are there other memory alignment / data type size modifications (other than pointers)?

  Read the article

• How to insert an integer into a database through command prompt

  - by jpavlov

  I am trying to insert a integer into a database in C# using the code below, but everytime I run the compiler informs me that my integer is not a valid column "Invalid Column Name UserID" Does anyone have any insight on this? Thanks. Console.WriteLine("Please enter a new User Id"); string line = Console.ReadLine(); int UserID; if (int.TryParse(line, out UserID)) { Console.WriteLine(UserID); Console.ReadLine(); } //Prepare the command string string insertString = @"INSERT INTO tb_User(ID,f_Name, l_Name) VALUES (UserID,'Ted','Turner')";

  Read the article

• vector<vector<largeObject>> vs. vector<vector<largeObject>*> in c++

  - by Leif Andersen

  Obviously it will vary depending on the compiler you use, but I'm curious as to the performance issues when doing vector<vector<largeObject>> vs. vector<vector<largeObject>*>, especially in c++. In specific: let's say that you have the outer vector full, and you want to start inserting elements into first inner vector. How will that be stored in memory if the outer vector is just storing pointers, as apposed to storing the whole inner vector. Will the whole outer vector have to be moved to gain more space, or will the inner vector be moved (assuming that space wasn't pre-allocated), causing problems with the outer vector? Thank you

  Read the article

• C# huge size 2-dim arrays

  - by 4eburek

  I need to declare square matrices in C# WinForms with more than 20000 items in a row. I read about 2GB .Net object size limit in 32bit and also the same case in 64bit OS. So as I understood the single answer - is using unsafe code or separate library built withing C++ compiler. The problem for me is worth because ushort[20000,20000] is smaller then 2GB but actually I cannot allocate even 700MB of memory. My limit is 650MB and I don't understand why - I have 32bit WinXP with 3GB of memory. I tried to use Marshal.AllocHGlobal(700<<20) but it throws OutOfMemoryException, GC.GetTotalMemory returns 4.5MB before trying to allocate memory. I found only that many people say use unsafe code but I cannot find example of how to declare 2-dim array in heap (any stack can't keep so huge amount of data) and how to work with it using pointers. Is it pure C++ code inside of unsafe{} brackets? Could you please provide a small example of working with matrices using pointers in unsafe code.

  Read the article

• Could Grand Central Dispatch (`libdispatch`) ever be made available on Windows?

  - by elliottcable

  I’m looking into multithreading, and GCD seems like a much better option than manually writing a solution using pthread.h and pthreads-win32. However, although it looks like libdispatch is either working on, or soon going to be working on, most newer POSIX-compatible systems… I have to ask, what about Windows? What are the chances of libdispatch being ported to Windows? What are the barriers preventing that from happening? If it came down to it, what would I need to do to preform that portage? Edit: Some things I already know, to get the discussion started: We need a blocks-compatible compiler that will compile on Windows, no? Will PLBlocks handle that? Can we use the LLVM blocks runtime? Can’t we replace all the pthread.h dependencies in userspace libdispatch with APR calls, for portability? Or, alternatively, use pthreads-win32 I suppose…

  Read the article

• Use WM_COPYDATA to send data between processes

  - by Charles Gargent

  I wish to send text between processes. I have found lots of examples of this but none that I can get working. Here is what I have so far: for the sending part: COPYDATASTRUCT CDS; CDS.dwData = 1; CDS.cbData = 8; CDS.lpData = NULL; SendMessage(hwnd, WM_COPYDATA , (WPARAM)hwnd, (LPARAM) (LPVOID) &CDS); the receiving part: case WM_COPYDATA: COPYDATASTRUCT* cds = (COPYDATASTRUCT*) lParam; I dont know how to construct the COPYDATASTRUCT, I have just put something in that seems to work. When debugging the WM_COPYDATA case is executed, but again I dont know what to do with the COPYDATASTRUCT. I would like to send text between the two processes. As you can probably tell I am just starting out, I am using GNU GCC Compiler in Code::Blocks, I am trying to avoid MFC and dependencies.

  Read the article

• Technology and language for a stable Digital Audio Workstation development

  - by Kill KRT

  Hi, I'm designing a cross platform (Windows/Linux/OS X) application, something like a digital audio workstation. I'd like to create a software where users have a fully featured sequencer (multiple tracks with automation) and where it is possible to create instruments using a visual language (as Pure Data/Max MSP). Ehm... I know that I've already posted a question about a related issue... But in order to decide which technology I should use, I think I'd better to make more investigation. I'm a quite experted user of audio trackers (Renoise, Protracker,...) and sequencers (FL Studio, Cubase 5), but I didn't ever try to develop even a basic audio tracker. I know just the basic theory of mixing sound and know how basically a DSP works. My questions are: Where I can find a good tutorial/guide/book about this issue? Do you think using C# (with NAudio) could dramatically reduce performance? I know C++ would be the best choice, but I find C# so elegant and easy to build and port, while C++ is so powerful and fast, but there are too #define and bad things for my taste! ;-) Thank you.

  Read the article

• How to learn to program C the right way

  - by sfactor

  i have been programming in C/C++ for my academic courses a lot and was under the impression i had a pretty good grasp of it. but lately i had to work in a bluetooth application that had a server and client implementation in a Linux box and an embedded system. i learned bluez bluetooth API, socket/network programming and coded it. however i ran into a lot of problems with memory leaks and segmentation faults and other memory related errors along the way.as the code grew more complex i all but lost control of the pointers and threads and sockets. this got me wondering that i had a lot to learn that they didn't say in the basic C/C++ books. so i wanted to ask for the resources that are available that'll help be code better in a professional way in C/C++ .especially for the Linux/Mac environment (gcc compiler).

  Read the article

• Using game of life or other virtual environment for artificial (intelligence) life simulation? [clos

  - by Berlin Brown

  One of my interests in AI focuses not so much on data but more on biologic computing. This includes neural networks, mapping the brain, cellular-automata, virtual life and environments. Described below is an exciting project that includes develop a virtual environment for bots to evolve in. "Polyworld is a cross-platform (Linux, Mac OS X) program written by Larry Yaeger to evolve Artificial Intelligence through natural selection and evolutionary algorithms." http://en.wikipedia.org/wiki/Polyworld " Polyworld is a promising project for studying virtual life but it still is far from creating an "intelligent autonomous" agent. Here is my question, in theory, what parameters would you use create an AI environment? Possibly a brain environment? Possibly multiple self contained life organisms that have their own "brain" or life structures. I would like a create a spin on the game of life simulation. What if you have a 64x64 game of life grid. But instead of one grid, you might have N number of grids. The N number of grids are your "life force" If all of the game of life entities die in a particular grid then that entire grid dies. A group of "grids" makes up a life form. I don't have an immediate goal. First, I want to simulate an environment and visualize what is going on in the environment with OpenGL and see if there are any interesting properties to the environment. I then want to add "scarce resources" and see if the AI environment can manage resources adequately.

  Read the article

• Hierarchical/Nested Database Structure for Comments

  - by Stephen Melrose

  Hi, I'm trying to figure out the best approach for a database schema for comments. The problem I'm having is that the comments system will need to allow nested/hierarchical comments, and I'm not sure how to design this out properly. My requirements are, Comments can be made on comments, so I need to store the tree hierarchy I need to be able to query the comments in the tree hierarchy order, but efficiently, preferably in a fast single query, but I don't know if this is possible I'd need to make some wierd queries, e.g. pull out the latest 5 root comments, and a maximum of 3 children for each one of those I read an article on the MySQL website on this very subject, http://dev.mysql.com/tech-resources/articles/hierarchical-data.html The "Nested Set Model" in theory sounds like it will do what I need, except I'm worried about querying the thing, and also inserting. If this is the right approach, How would I do my 3rd requirement above? If I have 2000 comments, and I add a new sub-comment on the first comment, that will be a LOT of updating to do. This doesn't seem right to me? Or is there a better approach for the type of data I'm wanting to store and query? Thank you

  Read the article

• How many instructions to access pointer in C?

  - by Derek

  Hi All, I am trying to figure out how many clock cycles or total instructions it takes to access a pointer in C. I dont think I know how to figure out for example, p-x = d-a + f-b i would assume two loads per pointer, just guessing that there would be a load for the pointer, and a load for the value. So in this operations, the pointer resolution would be a much larger factor than the actual addition, as far as trying to speed this code up, right? This may depend on the compiler and architecture implemented, but am I on the right track? I have seen some code where each value used in say, 3 additions, came from a f2->sum = p1->p2->p3->x + p1->p2->p3->a + p1->p2->p3->m type of structure, and I am trying to define how bad this is

  Read the article

• Are there any thead limitations that make it not print on each page in Firefox?

  - by SeanJA

  I have a table that has a <thead>, a <tfoot> and a <tbody>. It is supposed to print the thead and tfoot on each page in theory, but for some reason the thead does not if it contains certain elements together. This works: <thead> <tr> <td colspan="3">This works</td> <tr> <tr> <th colspan="2">column 1</th> <th> column 2 </th> </tr> </thead> This does not seem to work: <thead> <tr> <td colspan="3"> <h2>Header</h2> <address> <strong>address 1</strong> <br /> address 2 <br /> address 3 <br /> </address> <img src="/images/logo.png" alt="Logo" /> <h2>Another header</h2> <hr /> </td> </tr> <tr> <th colspan="2">column 1</th> <th> column 2 </th> </tr> </thead> Is there a reason for this not to work?

  Read the article

• Custom class object in Initialization list

  - by Michael

  I have a class Bar: class Bar { public: Bar(void); ~Bar(void); }; And a class Foo that gets a reference to Bar object as a constructor parameter and needs to save it in a private member bar_ : class Foo { private: Bar& bar_; public: Foo(Bar& bar) : bar_(bar) {} ~Foo(void) {} }; This doesn't compile : overloaded member function not found in 'Parser' missing type specifier - int assumed. Note: C++ does not support default-int Now i suspect couple of things that i need to assure, the second error is for Bar& bar_; declaration in Foo. Do i need to use an explicit constructor when declaring bar_ ? I am interested in learning how the compiler works regarding this matter, so a detailed explanation would be highly appreciated. Thanks.

  Read the article

• java.lang.UnsupportedClassVersionError in eclipse

  - by Derek

  Hi all, I am not a Java programmer really, so I am posting this question. The exception is being thrown java.lang.UnsupportedClassVersionError in my main class in an eclipse project. If I comment out the imports that this class has, it compiles and runs fine. If I put the imports back in, it does not work. Does this mean that the libraries I am importing were compiled with a newer or older version of java than I have? when i do java -version on the system i get 1.5_07 I could've sworn this was actually working last week, but maybe some setting in eclipse got tweaked? Is the Java Build Path in eclipse what I need to look for to check the JRE and compiler versions?

  Read the article

• Should I return an NSMutableString in a method that returns NSString

  - by Casey Marshall

  Ok, so I have a method that takes an NSString as input, does an operation on the contents of this string, and returns the processed string. So the declaration is: - (NSString *) processString: (NSString *) str; The question: should I just return the NSMutableString instance that I used as my "work" buffer, or should I create a new NSString around the mutable one, and return that? So should I do this: - (NSString *) processString: (NSString *) str { NSMutableString *work = [NSMutableString stringWithString: str]; // process 'work' return work; } Or this: - (NSString *) processString: (NSString *) str { NSMutableString *work = [NSMutableString stringWithString: str]; // process 'work' return [NSString stringWithString: work]; // or [work stringValue]? } The second one makes another copy of the string I'm returning, unless NSString does smart things like copy-on-modify. But the first one is returning something the caller could, in theory, go and modify later. I don't care if they do that, since the string is theirs. But are there valid reasons for preferring the latter form over the former? And, is either stringWithString or stringValue preferred over the other?

  Read the article

• addObjectsFromArray

  - by derek.lo

  I have a question about memory management when using the addObjectsFromArray method. Basically, I have 2 arrays defined in the appDelegate. I need these 2 arrays for the duration of my application's runtime. I therefore release them in my appDelegate's dealloc method. When I go to use these two arrays in a class, I want one array to store the values from the other, so that the other can have it's contents removed, but still stick around for use. Something like this: [appDelegate.arrayTwo addObjectsFromArray:appDelegate.arrayOne]; [appDelegate.arrayOne removeAllObjects]; I'm getting the compiler error: EXC_BAD_ACCESS because of a pointer issue? retaining issue? Any help would be greatly appreciated! Thanks

  Read the article

• Divide and conquer of large objects for GC performance

  - by Aperion

  At my work we're discussing different approaches to cleaning up a large amount of managed ~50-100MB memory.There are two approaches on the table (read: two senior devs can't agree) and not having the experience the rest of the team is unsure of what approach is more desirable, performance or maintainability. The data being collected is many small items, ~30000 which in turn contains other items, all objects are managed. There is a lot of references between these objects including event handlers but not to outside objects. We'll call this large group of objects and references as a single entity called a blob. Approach #1: Make sure all references to objects in the blob are severed and let the GC handle the blob and all the connections. Approach #2: Implement IDisposable on these objects then call dispose on these objects and set references to Nothing and remove handlers. The theory behind the second approach is since the large longer lived objects take longer to cleanup in the GC. So, by cutting the large objects into smaller bite size morsels the garbage collector will processes them faster, thus a performance gain. So I think the basic question is this: Does breaking apart large groups of interconnected objects optimize data for garbage collection or is better to keep them together and rely on the garbage collection algorithms to processes the data for you? I feel this is a case of pre-optimization, but I do not know enough of the GC to know what does help or hinder it.

  Read the article

• Force external function to be const

  - by vanna

  Here is my problem. I made a class with a member function declared as const that uses an external function that I cannot modify (declared in someone else's code) and that is not declared const. More precisely Someone else's code class B { public: void foo(); }; My code class A : public B { public: void bar() const { this->foo(); } }; I know that for member data we can force const-correctness by using mutable or const_cast. How can I 'hack' foo such that my compiler understands that I would like to use it as if it was const even if it is not declared in someone else's code ?

  Read the article

< Previous Page | 156 157 158 159 160 161 162 163 164 165 166 167  | Next Page >