c++

Create an grid array...

Okay so I am looking to create a grided array in OGRE3D game engine but the array is generic my array skills are pretty basic and need work so I am posting this just to be sure I am doing this correctly. #define GRIDWIDTH 10 #define GRIDHEIGHT 10 int myGrid [HEIGHT][WIDTH]; int n,m; int main () { for (n=0;n<HEIGHT;n++) for (m=0;...

RTTI and Portability in C++

If a compiler doesn't "support" RTTI, does that mean that the compiler can not handle class hierarchies that have virtual functions in them? Or have I been misunderstanding the literature about how RTTI isn't portable, and the issues lie elsewhere? Thank you all for your comments! ...

Using a variable in a mysql query, in a C++ MFC program.

Hi, after extensive trawling of the internet I still havent found any solution for this problem. I`m writing a small C++ app that connects to an online database and outputs the data in a listbox. I need to enable a search function using an edit box, but I cant get the query to work while using a variable. My code is: res = mysql_perf...

Throwing out of range exception in C++

This code works; int at(int index) { if(index < 1 || index >= size) throw 0; return x[index]; } Yet this doesn't int at(int index) { if(index < 1 || index >= size) throw std::out_of_range; return x[index]; } I get the error "expected primary expression before ';'". Now... it surprises me because I know std::out_o...

How to speed up calculation of length of longest common substring?

I have two very large strings and I am trying to find out their Longest Common Substring. One way is using suffix trees (supposed to have a very good complexity, though a complex implementation), and the another is the dynamic programming method (both are mentioned on the Wikipedia page linked above). Using dynamic programming The pr...

C++, generic programming and virtual functions. How do I get what I want?

This is what I would like to do using templates: struct op1 { virtual void Method1() = 0; } ... struct opN { virtual void MethodN() = 0; } struct test : op1, op2, op3, op4 { virtual void Method1(){/*do work1*/}; virtual void Method2(){/*do work2*/}; virtual void Method3(){/*do work3*/}; virtual void Method4(){/*...

convert int to string for use in allegro function

I am trying to run the following code using allegro. textout_ex(screen, font, numbComments , 100, 100, GREEN, BLACK); numbComments is an integer, the function prototype of this function is void textout_ex(BITMAP *bmp, const FONT *f, const char *s, int x, int y, int color, int bg); and i can...

Register C function in Lua table

How to register a C function in Lua, but not in a global context, but as a table field? ...

Is there a sorted_vector class, which supports insert() etc.?

Often, it is more efficient to use a sorted std::vector instead of a std::set. Does anyone know a library class sorted_vector, which basically has a similar interface to std::set, but inserts elements into the sorted vector (so that there are no duplicates), uses binary search to find elements, etc.? I know it's not hard to write, but p...

Trying to make a plugin system in C++/Qt

I'm making a task-based program that needs to have plugins. Tasks need to have properties which can be easily edited, I think this can be done with Qt's Meta-Object Compiler reflection capabilities (I could be wrong, but I should be able to stick this in a QtPropertyBrowser?) So here's the base: class Task : public QObject { Q_OBJECT ...

Setting Position of source and listener has no effect

Hi Guys, First time i've worked with OpenAL, and for the life of my i can't figure out why setting the position of the source doesn't have any effect on the sound. The sounds are in stero format, i've made sure i set the listener position, the sound is not realtive to the listener and OpenAL isn't giving out any error. Can anyone shed ...

Mixing Objective-C and C++

Hello, I'm trying to mix together some Objective-C code with C++. I've always heard it was possible, but I've never actually tried it before. When I try to compile the code, I get a bunch of errors. Here's a simple example I've created which illustrates my problems: AView.h #import <Cocoa/Cocoa.h> #include "B.h" @interface AView : ...

initializing structs using user-input information

I am trying to make a program that works with poker (texas holdem) starting hands; each hand has a value from 1 to 169, and i want to be able to input each card and whether they are suited or not, and have those values correspond to a series of structs. Here is the code so far, i cant seem to get it to work (im a beginning programmer). ...

Linked List push()

The stack is initialized with a int MaxSize =3. Then I push one int onto the list. " Pushed:" is returned to the console. Program crashes here. I think my logic is flawed but unsure. Maybe an infinite loop or unmet condition? Thanks for your help. I'm trying to traverse the list to the last node in the second part of the full()...

Where can I find the source code for a task queue implemented by C++ for Open MPI

hi Where can I find the source code for a task queue implemented by C++ for Open MPI ? I search it online, but cannot find it. Any help is appreciated. thanks Jack April 25 2010 ...

bitset to dynamic bitset

Hi.. I have a function where i use bitset.Now i need to convert it to a dynamic bitset.. but i don't know how. Can somebody help me ? set<string> generateCandidates(set<string> ck,unsigned int k){ set<string> nk ; for (set<string>::const_iterator p = ck.begin( );p != ck.end( ); ++p){ for (set<string>::const_iterator q = ck.begin(...

Using a type parameter and a pointer to the same type parameter in a function template

Hello, I've written a template function to determine the median of any vector or array of any type that can be sorted with sort. The function and a small test program are below: #include <algorithm> #include <vector> #include <iostream> using namespace::std; template <class T, class X> void median(T vec, size_t size, X& ret) { so...

What is the correct less operator for simple class with two int members?

What is the correct operator< for the following class? struct Person { int height; int width; friend bool operator<(const Person&, const Person&); }; Thanks! ...

No-op deallocator for boost::shared_ptr

Is there a stock no-op deallocator in Boost to use with boost::shared_ptr for static objects, etc. I know it's ultra-trivial to write, but I don't want to sprinkle my code with extra tiny functions if there is already one available. ...

How many numbers in an array are smaller than a given number?

The naive one is O(n). Is there a one that is O(log n) or even O(1)? How about a sorted array? How about using binary search tree? How about my array has a size n = [2 ^(h + 1)] − 1 ? // h=height of a complete binary tree ...