2,898 Posted Topics
 | He's basically right. But I don't like his or your terminology. A pointer stores a memory address. When you use the new operator, you allocate a chunk of memory (either for a single object or for an array of objects) and it returns the address of the allocated memory, which …  |
| | I think the only problem is a misplaced closing bracket. If you move the closing bracket at line 42 to line 56, then all should work. Right now, line 42 is where the while-loop ends, but it should end at line 56. Hint: Using proper indentation will help you identify … |
| | It's a simple typo. Line 14 should be: Test((void*)F); // notice no & here. Because when you do `&F`, the type of that expression will be `std::function<void()>**`, and then, later you cast that into the type `std::function<void()>*`, and thus, the crash (or undefined behavior). |
| | It is generally not recommended to do this at all. There is always the danger of the [static initialization order fiasco](http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.14). I'm not sure how safe it is to do this for a standard component like `cout`. The safest thing is to just define a function that will perform this …  |
 | I'm an atheist, and have always been. My mother was born a catholic but was pushed away from it due to the horrible and discusting actions of the catholic church in the 50s, 60s and 70s, and once she left and stop being reinforced in the belief in God, the …  |
| | > First, why does this not cause a stack overflow? If you call a function in an infinite loop, you will not get a stack overflow. The stack is, well, a stack. Things get pilled on and pulled off. You enter a function, it uses some space on the stack … |
| | I just filled it. I hope you get a lot of people to fill it too, I will be interesting to see the results. |
 | Re: samba For the samba problem, just run a search like this: $ aptitude search samba and it will print the list of packages with the name "samba" in it. You can just install all the packages that are relevant from that list. If a package appears in the list, then you … |
| | Re: ld-linux.so.2 The library should be part of "glibc" package, which is a fundamental system package, I doubt that you lack it. To find the `ld-linux.so.2` try to run this command: $ locate ld-linux It is possible that the file in question appears in the wrong directory, like `/lib64` or something. You … |
| | This is a great start! You have clearly put some effort into it. The easiest way to solve this problem with the inputs of the rational numbers is to create a separate function for inputting and outputting a rational number. And the best way to do this is to overload … |
 | I find that Python is a really nice language to learn in addition to C++, because it is very different (very high-level), easy, and it works very well along-side C++ (Python is often used as a high-level scripting language to use to run C++ code, through python-bindings). > I read … |
 | I just wanted to point this out. Another solution is to simply attempt to compile everything with the C++ compiler. Technically, a C++ compiler cannot compile *any* C code, but it can compile *most* C code. Of course, if the C code is a large code-base and all, you shouldn't …  |
| | Well, I happen to have written a tutorial on how to write a class like that. Read it [here](http://www.daniweb.com/software-development/cpp/tutorials/373787/beginning-c0x-making-a-raii-class). Your class is no different than the standard [`std::vector`](http://www.cplusplus.com/reference/stl/vector/) class (except that the standard class has way more features). So, I recommend you use that instead. |
| | You can assume, for all practical matter, that the `std::vector` class just stores two fields: the size of the array and a pointer to the first element of the array. In other words, this is the same as what you would have to do if you allocated the dynamic array … |
| | I ran your code and I get exactly what is expected. That is, I called `$ ./clone_test 2` and I got this output: PID = 27719 PPID = 27718 PID(child of a child) = 27720 PPID(child of a child) = 27719 PID = 27721 PPID = 27718 PID(child of a … |
| | Did it occur to you that you can test this out very easily? When it comes to performance, the only thing that can settle the argument is test results, the rest is just speculative non-sense. Try this: #include <iostream> #include <ctime> #include <algorithm> #include <cstring> #include <iomanip> union Record { … |
| | The general rule is this: 1. Prefer declaring / defining your operator overloads as non-member functions; 1. If you need access to private members, make them non-member friend functions; 1. If that particular type of operator must be a member function (like the assignment operator, or conversion operators), then make … |
| | I am currently working on kind of multi-graph structure. The thing is that two graphs are needed for my application which span the same vertices but with two distinct set of edges (i.e., a multi-graph). The first graph is a binary search tree, while the second graph must be general … |
| | You've been busy! Pretty nice code you have there. There is one important mistake for sure, you allocate your pixel array as `Pixels = new RGB[size];` where size is the size in **bytes** of the image. So, you need to allocate the pixels as `Pixels = new RGB[width * height];`. … |
| | You can also try to download the package separately and manually swap it. You can download the package from [here](http://pkgs.org/ubuntu-12.04/ubuntu-main-amd64/e2fsprogs_1.42-1ubuntu2_amd64.deb.html). If the problem persists after you have checked the MD5 checksum, then you should report it to ubuntu bug-tracking. |
 | Well, DeanMSands3 was right about one thing: the original loop was erroneous. The correct solution is this: indices = malloc (sizeof(short) * data.face_count * 3); for (i = 0; i < data.face_count; i++); // notice i++ and not i += 3 { indices[3 * i] = data.face_list[i]->vertex_index[0]; indices[3 * i …  |
| | And, if you want the numbers to be aligned to the right, you have to put the setw immediately before you print the number and you can also use setprecision to have only two numbers after the dot (for floating-point numbers), as in: cout << setprecision(2); cout << setw(23) << … |
| | Here are some initial comments: **Style** Overall the coding style is OK, but a bit unusual. Naming functions like `Pull_randWord` is a bit unusual, but more importantly, it is not consistent with the rest of the code, you should pick one style and make it consistent. Then, using all upper-case …  |
| | Re: ssh-scp Well, first of all, there's a typo in what you have posted. In the source path, `developer@192.168.1.9:/home/develope/fromlaptopsaveDeveloper.tar.gz`, you are missing the R in `developer` folder name. It could very well be just that. Otherwise, your destination is weird. You send the file to the desktop under username garrett, but the … |
 | Your operator overload is for `Element + Element` not for `int + Element` or `Element + int`. You can fix the problem by defining those operator overloads, as free-functions: Element operator+(const Element& lhs, int rhs); Element operator+(int lhs, const Element& rhs); and implementing them as you see fit. BTW, it … |
| | Re: Amost done There are a few issues with your code. First, your ImplementCalculations function doesn't need to take those three parameters because they are already part of the class (and object). Also, you should probably name the function a bit better, like "ComputeOvertime" or something like that. Second, you probably shouldn't call … |
 | Re: Shell Commands? Git is built like most other Unix/Linux tools, as a set of command-line tools (programs) with options. The best library for the purpose of creating an option-rich command-line program is the [Boost.Program-Options](http://www.boost.org/doc/libs/1_49_0/doc/html/program_options.html). If what you want to do is create a shell program (like bash), then it's a whole other … |
| | Why does the compilation of "main.cpp" trigger error reports coming from "player.cpp"? You are not `#include`ing "player.cpp" from your "main.cpp" file, are you? This has to be coming from an undeclared type or variable. The real error is at "player.cpp" at line 43, the rest is just noise from the … |
 | If I was able to travel back in time, I would probably also be able to travel very large distances instantly. I think I would travel back to a long time ago in a galaxy far, far away....  |
| | > I am more interested in knowing if a certain distribution of Linux is better supported for Hadoop and why? Don't know about Hadoop specifically, but I would imagine that Red Hat Enterprise Linux (Server) is one of the best OS for this application (and by "best OS", I don't … |
| | Well, maybe you should start by trying to locate the declarations of `HT` and `pos`, because, as the compiler says, they are not declared in that scope. For your function prototype to be valid, `HT` should be a type and `pos` should be a `#define`. I see no such thing … |
| | Re: help with openGL Well, obviously, you can't hard-code the vertices into your program (your post almost made it sound like that is what you are trying to do). You must store the mesh (list of vertices and polygons) into a file that you can load and display. Or, you should generate simple geometric … |
| | I believe you need a parent QWidget for your new window. And, I also think that your window should be persistent, if you are going to just `show()` it (as opposed to `exec()` it). So, I think that the following should work better: class MainWindow : public QMainWindow { Q_OBJECT … |
| | The guidelines for the two algorithms are basically the same as for their respective mother-algorithms, i.e., the sorting algorithms. The counting-selection algorithm is only applicable to a very tightly packed integer-valued array. What I mean by that is that the bound (`cap` in your function) has to be very small, … |
| | You need to `delete` every thing that has been allocated with `new`. It's as simple as that. In practice, however, it can be complicate to ensure that nothing is left behind (undeleted). There are many techniques and guidelines to follow in order to help you with that. I wrote two … |
| | The compilation success is contigent on the fact that the compiler allows `0` to be implicitly converted to the pointer type `DOMNode*`. I'm not sure what is the standard behavior required here. In general, if you replace `0` with `NULL`, it should work, because `NULL` must be convertible to any …  |
| | > Would anyone know what is meant by dynamically linking to qt libraries?? Well, this is just a matter of knowing what dynamic linking means. Take [wiki](http://en.wikipedia.org/wiki/Dynamic-link_library) for a start. As a quick explanation, let me start from the basics. You have some code. In a usual project, you'll have … |
 | Re: Code style > starting names of all classes and variables of composit data types with capital and of base types with a small letter. That is very odd indeed. The most important thing about coding conventions, is that they should be conventional. It's like with a standard, it doesn't matter as much … |
 | It's a trade-off between speed and safety. Generally, in many places, C++ standard libraries and their implementations put the emphasis on speed. This is why many STL container functions do not have bounds checking (or they have it only as an `assert` condition), although there are bound-checked alternatives like the … |
 | Congrats on your fourth grand-kid! I'm really sorry to hear about your eye affliction.. I wish you the best of luck and success in treatments. Being the robotic geek that I am, I have to mention this. Coincidently, a couple of weeks ago, I just attended [this plenary talk](http://www.icra2012.org/program/schedule.php) (which … |
 | That program is equivalent to this: if(A + B < 20) A = A + 5; else A = A - 1; Line-by-line, you have: LOAD A ADD B Puts the variable A on the register, and then adds the value of B to that. So, it computes `A + … |
| | The errors are due to the fact that this assembly code is not real assembly code. This is just a simplified syntax to teach the logic of it. The actual syntax is quite a bit more complicated. Here is the AT&T syntax that is equivalent to your program ("AT&T" syntax … |
| | Calculating the complexity of an algorithm is really just a matter of figuring out how many times an operation will be done. If you take the outer loop, `for(int i = 1; i <= n; i *= 2)`, you can ask yourself how many iterations will be executed. If n … |
| | > please note that i am reading a file that consits of all characters (ascii 0-255) therefore i must use wstring instead of string.. I doubt that this is true. A normal character (`char`) is one byte in size, and it can represent 256 characters (many of which don't actually … |
| | You must transfer the data into an array (or vector) that you can use to manipulate the data. Then, you save the data back to the file, overwriting it. The rdbuf is really not meant for you to tamper with, and you certainly cannot use it to modify the content … |
| | > The function rand_0toN1 returns rand() % n, in this case I believe that it's returning a random number from 1-10 because 10 was passed as an argument through n, which is not the same n that was declared at the beggining of the program but local to the function …  |
 | > but there's no further explanation why i must convert the it to cstring, anyone knows? Yeah, I know. The reason is because of the original design of the libraries, in particular the iostream and the string library. Basically, they were developed more or less in isolation, and iostream came … |
| | Re: Inverse Matrix This is not a program, it is a function. What it does is to compute the inverse of a matrix through a [Gaussian elimination](http://en.wikipedia.org/wiki/Gaussian_elimination). The implementation itself is very naive, meaning that it is inefficient, numerically unstable, and also programmed in bad style, not to mention that this is basically … |
| | The library to do this is called winsock. This is a standard Windows library and it is usually installed with any compiler you have and is also pretty simple to use. You can following [this msdn guide](http://msdn.microsoft.com/en-us/library/windows/desktop/ms738545(v=vs.85).aspx) to get acquainted with the library. If you have any more specific questions … |
| | You have a massive memory-leaking loop. No surprise that it crashes your system. In the loop inside main, you allocate B objects and never delete them. This is a more correct loop: for(int i = 0; i < 1000000; i++) { A* obj = new B(); obj->foo(); delete obj; // … |
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