Search Results

Search found 5729 results on 230 pages for 'compiler dependent'.

Page 168/230 | < Previous Page | 164 165 166 167 168 169 170 171 172 173 174 175  | Next Page >

  • 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.

    Read the article

  • Undefined method for a belongs_to association

    - by marimaf
    My code: class User < ActiveRecord::Base belongs_to :university end class University < ActiveRecord::Base has_many :users, dependent: :destroy end and my model User has a university_id attribute. If I do University.find(1).users I get the list of users, but if I do User.find(1).university (and I checked that university_id is not nil here) I get: NoMethodError: undefined method `university' for from /home/mari/.rvm/gems/ruby-1.9.2-p290/gems/activemodel-3.0.10/lib/active_model/attribute_methods.rb :392:in `method_missing' from /home/mari/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.0.10/lib/active_record/attribute_methods. rb:46:in `method_missing' from (irb):14 from /home/mari/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.10/lib/rails/commands/console.rb:44:in sta rt' from /home/mari/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.10/lib/rails/commands/console.rb:8:in star t' from /home/mari/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.0.10/lib/rails/commands.rb:23:in <top (requi red)>' from script/rails:6:inrequire' from script/rails:6:in `' What am I doing wrong? I have another models and they are working just fine. Any suggestions? Thanks in advance

    Read the article

  • namespacing large javascript like jquery

    - by frenchie
    I have a very large javascript file: it's over 9,000 lines. The code looks like this: var GlobalVar1 = ""; var GlobalVar2 = null; function A() {...} function B(SomeParameter) {...} I'm using the google compiler and the global variables and functions get renamed a,b,c... and there's a good change that there might be some collision later with some outside code. What I want to do is have my code organized like the jquery library where everything is accessible with $. Is there a way to namespace my code so that everything is behind a # character for example. I'd like to have this to call my code: #.GlobalVar #.functionA(SomeParameter) How can I do this? Thanks.

    Read the article

  • Why are types found on an imported namepace but not on a fully qualified namespace after retargeting the framework?

    - by Paul Ferguson
    We've just re-targeted a VB.NET project from .Net 2.0 to 3.5. Various framework types are now missing from our project. Wherever the type is referenced using a fully qualified namespace it's missing. If the relevant namespace is imported for the type; it's found. For example, this doesn't find the type Object, with compiler error "System.Object is not defined.": Public Class Foo Inherits System.Object End Class However, this works ok: Imports System Public Class Foo Inherits [Object] End Class I've already tried re-opening the solution with no success.

    Read the article

  • C++ template nontype parameter arithmetic

    - by aaa
    hello I am trying to specialize template the following way: 132 template<size_t _1,size_t _2> 131 struct integral_index_ {}; ... 141 template<size_t _1> 142 struct integral_index_<_1, _1 + 1> { ... 148 }; however I get compiler message error the template argument list of the partial specialization includes a non -type argument whose type depends on a template parameter. what do my doing wrong? thanks

    Read the article

  • C++: How to use types that have not been defined?

    - by Jen
    C++ requires all types to be defined before they can be used, which makes it important to include header files in the right order. Fine. But what about my situation: Bunny.h: class Bunny { ... private: Reference<Bunny> parent; } The compiler complains, because technically Bunny has not been completely defined at the point where I use it in its own class definition. This is not sufficient: class Bunny; class Bunny { ... private: Reference<Bunny> parent; } Apart from re-writing my template class Reference so it takes a pointer type (in which case I can use the forward declaration of Bunny), I don't know how to solve this. Any suggestions?

    Read the article

  • What could possibly cause this error(when declaring an object inside a class) ? //noobie question

    - by M4design
    I'm battling with this assignment :) I've got two classes: Ocean and Grid. When I declare an object of the Grid inside the Ocean: unsigned int sharkCount; Grid grid; The compiler/complainer says: error C2146: syntax error : missing ';' before identifier 'grid' Can you possibly predict what produces this error with the limited info' I provided? It seems that as if the Ocean doesn't like the Grid class. Could this be because of the poor implementation of the grid class. BTW the Grid has a default constructor. Yet the error happens in compiling time!. Thanks. EDIT: They're each in separate header file, and I've included the Grid.h in the Ocean.h.

    Read the article

  • Function calls in virtual machine killing performance

    - by GenTiradentes
    I wrote a virtual machine in C, which has a call table populated by pointers to functions that provide the functionality of the VM's opcodes. When the virtual machine is run, it first interprets a program, creating an array of indexes corresponding to the appropriate function in the call table for the opcode provided. It then loops through the array, calling each function until it reaches the end. Each instruction is extremely small, typically one line. Perfect for inlining. The problem is that the compiler doesn't know when any of the virtual machine's instructions are going to be called, as it's decided at runtime, so it can't inline them. The overhead of function calls and argument passing is killing the performance of my VM. Any ideas on how to get around this?

    Read the article

  • Inline function v. Macro in C -- What's the Overhead (Memory/Speed)?

    - by Jason R. Mick
    I searched Stack Overflow for the pros/cons of function-like macros v. inline functions. I found the following discussion: Pros and Cons of Different macro function / inline methods in C ...but it didn't answer my primary burning question. Namely, what is the overhead in c of using a macro function (with variables, possibly other function calls) v. an inline function, in terms of memory usage and execution speed? Are there any compiler-dependent differences in overhead? I have both icc and gcc at my disposal. My code snippet I'm modularizing is: double AttractiveTerm = pow(SigmaSquared/RadialDistanceSquared,3); double RepulsiveTerm = AttractiveTerm * AttractiveTerm; EnergyContribution += 4 * Epsilon * (RepulsiveTerm - AttractiveTerm); My reason for turning it into an inline function/macro is so I can drop it into a c file and then conditionally compile other similar, but slightly different functions/macros. e.g.: double AttractiveTerm = pow(SigmaSquared/RadialDistanceSquared,3); double RepulsiveTerm = pow(SigmaSquared/RadialDistanceSquared,9); EnergyContribution += 4 * Epsilon * (RepulsiveTerm - AttractiveTerm); (note the difference in the second line...) This function is a central one to my code and gets called thousands of times per step in my program and my program performs millions of steps. Thus I want to have the LEAST overhead possible, hence why I'm wasting time worrying about the overhead of inlining v. transforming the code into a macro. Based on the prior discussion I already realize other pros/cons (type independence and resulting errors from that) of macros... but what I want to know most, and don't currently know is the PERFORMANCE. I know some of you C veterans will have some great insight for me!!

    Read the article

  • Constructing a function call in C

    - by 0x6adb015
    Given that I have a pointer to a function (provided by dlsym() for example) and a linked list of typed arguments, how can I construct a C function call with those arguments? Example: struct param { enum type { INT32, INT64, STRING, BOOL } type; union { int i32; long long i64; char *str; bool b; } value; struct param *next; }; int call_this(int (*function)(), struct param *args) { int result; /* magic here that calls function(), which has a prototype of f(int, long long, char *, bool); , when args consist of a linked list of INT32, INT64, STRING, BOOL types. */ return result; } The OS is Linux. I would like the solution to be portable across MIPS, PPC and x86 (all 32 bits) architecture, using GCC as the compiler. Thanks!

    Read the article

  • Will Algorithm written in OCaml compiled from C be Faster than Algorithm written in Pure C code?

    - by Ole Jak
    So I have some cool Image Processing algorithm. I have written it in OCaml. It performs well. I now I can compile it as C code with such command ocamlc -output-obj -o foo.c foo.ml (I have a situation where I am not alowed to use OCaml compiler to bild my programm for my arcetecture, I can use only specialy modified gcc. so I will compile that programm with sometyhing like gcc -L/usr/lib/ocaml foo.c -lcamlrun -lm -lncurses and Itll run on my archetecture.) I want to know in general case will my OCaml code compiled into C run faster than algorithm implemented in pure C?

    Read the article

  • "Abstract static" method - how?

    - by polyglot
    There are already several SO questions on why there is not abstract static method/field as such, but I'm wondering about how one would go about implementing the following psuedo-code: class Animal { abstract static int getNumberOfLegs(); // not possible } class Chicken inherits Animal { static int getNumberOfLegs() { return 2; } class Dog inherits Animal { static int getNumberOfLegs() { return 4; } Here is the problem: Assuming that I want make sure that every class that inherits Animal to contain getNumberOfLegs() method (i.e. almost like an interface, except I do want the abstract class to implement several methods that are common to all child classes, hence pure interface does not work here). getNumberOfLegs() obviously should be a static method (assuming that in a perfect world we dont' have crippled chicken and dogs so getNumberOfLegs is not instance-dependent). Without an "abstract static" method/field, one can either leave the method out from Animal class, then there is the risk that some child class do not have that method. Or one can make getNumberOfLegs an instance method, but then one would have to instantiate a class to find out how many legs that animal has - even though it is not necessary. How do one usually go about implementing this situation?

    Read the article

  • Portable Eclipse

    - by Jeach
    I'm trying to port my entire 'workspace' to a USB key (including the Eclipse executable) so that I can carry my work anywhere with me and work off the key directly. My directory hierarchy is similar to this: /workspace/eclipse - Where my current eclipse binary is stored /workspace/codebase - Where I keep the root of all my eclipse projects /workspace/resources - Where I keep all project files (images, docs, libs, etc.) It all works perfectly fine on one system. But when I change over to another system, the USB key gets mounted on another drive. For example, on my laptop, I get 'E:\', on my PC, I get 'K:\' and at work I get 'F:\', etc, etc. This means that because Eclipse (for 'some' reason) seems to only use full path names (including driver letters) in every single one of its configuration files (such as .classpath), nothing ever works when I want to work on another system. I put a 'libs' directory in the base of every project and populate it with its dependent JAR files. Why doesn't it use relative names instead, so that I could specify something like "../../libs/log4j.jar"? Anyone know how to fix this problem? Does anyone know of a workaround for this? For some reason, I really doubt I'm the first developer to do this! Thanks for your help and any suggestions.

    Read the article

  • How can I resolve naming conflict in given precompiled libraries?

    - by asm
    I'm linking two different libraries that have functions with exactly same name (it's opengl32.lib and libgles_cm.lib - OpenGL ES emulation under Win32 platform), and I want to be able to specify, which version I'm calling. I'm porting a game to OpenGL ES, and what I want to achieve, is a split-screen rendering, where left side is an OpenGL version, and right side is a ES version. To produce the same result, they will recieve slightly different calls, and I'll be able to visually compare them, effectively finding visual artifacts. It worked perfectly with OpenGL/DirectX at the same window, but now the problem is that both versions imports the functions with the same name, like glDrawArrays, and only one version is imported. Unfortunately, I don't have sources of any of that libraries. Is there a way to... I dont' know, wrap one library into additional namespace before linking (with calls like ES::glDrawArrays), somehow rename some of functions or do anything else? I'm using microsoft compiler now, but if there will be solution with another one (GCC/ICC), I'll switch to it.

    Read the article

  • Memory management for "id<ProtocolName> variableName" type properties

    - by Malakim
    Hi, I'm having a problem with properties of the following type: id<ProtocolName> variableName; ..... ..... @property (nonatomic, retain) id<ProtocolName> variableName; I can access and use them just fine, but when I try to call [variableName release]; I get compiler warnings: '-release' not found in protocol(s) Do I need to define a release method in the interface, or how do I release the memory reserved for the variable? Thanks!

    Read the article

  • Performance problem loading lots of user controls

    - by codymanix
    My application is loading a bunch of the same user control into a ScrollPanel. The problem is, this is very slow. The profiler show that the method Application.LoadComponent(), which is called internally by in the designer code in the constructor of my user control, is the bottleneck. The documentation of this method says, that this method load XAML files. I alway though the compiler compiles XAML to BAML and embedds it into the assembly. So the question is, how can I use BAML instead of XAML? Is there another way to make loading my user controls faster?

    Read the article

  • C++: namespace conflicht 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 funcition solve in my C++ member function A::solve. The compiler is not happy with my intents: error C2664: 'lp_solve_ilp::solve' : cannot convert parameter 1 from 'lprec *' to 'int' Is there something I can prefix the solve function? C::solve does not work

    Read the article

  • Java Beginner Question : What is wrong with the code below ?

    - by happysoul
    public class Function { public static void main(String args[]) { System.out.println(power(3,2)); System.out.println(power(3,2)); System.out.println(power(2)); } public long power(int m) { return m*m; } public long power(int m,int n) { long product=1; for(int i=1;i<=n;i++) { product=product*m; } return product; } } Compiler displays this error :- Function.java:5: non-static method power(int,int) cannot be referenced from a static context

    Read the article

  • Is It Safe to Cast Away volatile?

    - by Yan Cheng CHEOK
    Most of the time, I am doing this way. class a { public: ~ a() { i = 100; // OK delete (int *)j; // Compiler happy. But, is it safe? // Error : delete j; } private: volatile int i; volatile int *j; }; int main() { a aa; } However, I saw an article here: https://www.securecoding.cert.org/confluence/display/seccode/EXP32-C.+Do+not+access+a+volatile+object+through+a+non-volatile+reference Casting away volatile allows access to an object through a non-volatile reference. This can result in undefined and perhaps unintended program behavior. So, what will be the workaround for my above code example?

    Read the article

  • functions in assembler

    - by stupid_idiot
    hi, i have philosophised about the purpose of stack a little bit and after some coding i figured out what is it's strength. The only thing that lies in my stomache is how does it work with functions? I tried to make some easy function for adding two numbers using universal registers but I suppose that's not how does it work in C for example.. where are all the parameters, local variables and where is the result stored? how would you rewrite this to assembler?(how would compiler for C rewrite it?) int function(int a, int &b, int *c){ return a*(b++)+(*c); } i know this example kinda sucks.. but this way i can understand all the possibilities

    Read the article

  • Windows based development for ARM processors

    - by user367231
    I am a complete newbie to the ARM world. I need to be able to write C code, compile it, and then download into an ARM emulator, and execute. I need to use the GCC 4.1.2 compiler for the C code compilation. Can anybody point me in the correct directions for the following issues? What tool chain to use? What emulator to use? Are there tutorials or guides on setting up the tool chain?

    Read the article

  • initialization of objects in c++

    - by Happy Mittal
    I want to know, in c++, when does the initialization of objects take place? Is it at the compile time or link time? For ex: //file1.cpp extern int i; int j=5; //file2.cpp ( link with file1.cpp) extern j; int i=10; Now, what does compiler do : according to me, it allocates storage for variables. Now I want to know : does it also put initialization value in that storage or is it done at link time?

    Read the article

  • 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?

    Read the article

  • Using a class with const data members in a vector

    - by Max
    Given a class like this: class Foo { const int a; }; Is it possible to put that class in a vector? When I try, my compiler tells me it can't use the default assignment operator. I try to write my own, but googling around tells me that it's impossible to write an assignment operator for a class with const data members. One post I found said that "if you made [the data member] const that means you don't want assignment to happen in the first place." This makes sense. I've written a class with const data members, and I never intended on using assignment on it, but apparently I need assignment to put it in a vector. Is there a way around this that still preserves const-correctness?

    Read the article

  • Compile Qt Project To Run On A Linux System

    - by ForgiveMeI'mAN00b
    I have a Qt project. It uses the cross platform libraries SDL, OpenGL and FLTK. I want to be able to compile the project so that it can run on a Linux computer. I'm looking at a bunch of articles I have seen so far two ways to do this. Use a cross compiler, which seems to me a rather complicated thing to setup and compile with, or, the other options, is to compile the project simply on a Linux computer, simply the Linux version of Qt creator/SDK. My question is, If I have a Qt project that uses only cross platform libraries, then is creating a Windows version easy as compiling it in Qt/Windows, and creating the Linux version as easy as doing it in Qt/Linux? PS. Please don't ask/complain about why I didn't just try to see if it works myself, I don't have any Linux OS's installed on my computer right now, and I don't want to risk going into the trouble of installing a whole new OS just to have it not work in the end.

    Read the article

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