Considering the basic data types like char, int, float, double etc..in any standard language C/C++, Java etc Is there anything like.."operating on integers are faster than operating on characters".. by operating I mean assignment, arithmetic op/ comparison etc. Are data types slower than one another? ...
I am very disappointed with my school linux server when doing the homework on it. The reason is: my homework requires to make GUI application. All the tool that I have is: - ssh from my local machine to school machine - gcc/g++ in my school machine I have been thinking and tried out different solutions for a week. I still can't be ...
I wrote a judgment code of even/odd numbers with C++ templates. #include <iostream> template <int N, int Mod2=N%2> struct Print { Print() { std::cout << N << std::endl; } }; template <int N> struct Print<N, 0> { Print() { std::cout << "Even!" << std::endl; } }; template <int N> struct Print<N, 1> { Print() { std...
I mean, I malloc a segment of memory, maybe 1k maybe 20bytes.. assume the pointer is pMem How can I know the content pMem refered is all Zero or \0 . I know memcmp but the second parameter should another memory address... thanx ...
Q1. Why does using NULL pointers with static_cast cause crashes while dynamic_cast and reinterpret_cast give a NULL pointer in return? The problem occurred in a method similar to the one given below: void A::SetEntity(B* pEntity, int iMyEntityType) { switch (iMyEntityType) { case ENTITY1: { Set1(static_cast<C...
I am having trouble to write the binary algorithm in C/C++. My question is like that: Apply binary algorithm to search for a number from 1 to 100 in a number guessing game. The user will respond with 'y' for a correct guess, 'h' if the guess is too high or 'l' if the guess is too low. I don't have any idea to apply it. Can someone ju...
Hi how to represent a graph with list data structure i have three class (Graph, Node, Edge) and would like to find the critical path in graph. how to calculate ES : Earliest Start EC : Earliest Complete LS : Latest Start LC : Latest Complete thanks ...
I've got a loop in my code that uses std::basic_string<HANDLE>, and then waits on it like this: DWORD dwWaitResult = WaitForMultipleObjects((DWORD)handles.size(), handles.data(), FALSE, POLL_INTERVAL_MS); It works fine, but when I turn on /W4 and /...
Consider this scenario: An application links to 3rd party library A. A is built using MSVC 2008 and is statically linking (ie. built with /MT) to the C Runtime Library v9.0. The application is built using MSVC 2005 and is statically linking to A and (using /MT) to the C Runtime Library v8.0. I can see trouble with this - for instance ...
I'm looking for a framework / approach to do message passing distributed computation in C++. I've currently got an iterative, single-threaded algorithm that incrementally updates some data model. The updates are literally additive, and I'd like to distribute (or at least parallelize) the computation hereof over as many machines+cores a...
I have a notion that C++ runtime doesn't do any heap compaction which means that the address of an object created on heap never changes. I want to confirm if this is true and also if it is true for every platform (Win32, Mac, ...)? ...
Hi All! I want to implement a simple class for logging from multiple threads. The idea there is, that each object that wants to log stuff, receives an ostream-object that it can write messages to using the usual operators. The desired behaviour is, that the messages are added to the log when the stream is flushed. This way, messages wil...
I'm making a game and I have stored the map data in a 2-dimensional array of size [34][10]. Originally I generated the map using a simple function to fill up the array and saved this data to a file using the following code: ofstream myFile; myFile.open("map.txt"); for ( int y = 0 ; y < MAP_HEIGHT ; ++y ) { for ( int x = 0 ; x < MAP_WI...
Is there a reliable method to check if an application is run from somewhere beneath program files? If the user installs the application to program files on local machine, we need to put writable files somewhere else to avoid virtualization on Vista and Win7. When installed to a network disk, though, we want to keep these files with the ...
I want to use Qt to create a simple GUI application that can play a local video file. I could use Phonon which does all the work behind the scenes, but I need to have a little more control. I have already succeeded in implementing an GStreamer pipeline using the decodebin and autovideosink elements. Now I want to use a Qt widget to chann...
Hi I wanted know the reasons of the following code void main() { class test { public: test(){} int k; }; class test1 { public: test1(){} int k; }; union Test { test t1; test1 t2; }; } For the Above code it gives error "error C2620: union 'Test' : member 't1' has user-defin...
I'm writing a performance critical application where its essential to store as much data as possible in the physical memory before dumping to disc. I can use ::GlobalMemoryStatusEx(...) and ::GetProcessMemoryInfo(...) to find out what percentage of physical memory is reserved\free and how much memory my current process handles. Using ...
I need to convert a short value from the host byte order to little endian. If the target was big endian, I could use the htons() function, but alas - it's not. I guess I could do: swap(htons(val)) But this could potentially cause the bytes to be swapped twice, rendering the result correct but giving me a performance penalty which is ...
I'm checking the results from the static code analysis tool Klocwork. It complains about the following code: 293 for( my_vector_typedef::iterator it( start_pos ); it != end_pos ; ++it ){ 294 delete *it; 295 } With the following message: Object 'it._M_current' is used after it was freed. Object 'it._M_current' was used at line 293 ...
Hello, here's today's dilemma: suppose I've class A{ public: virtual void doit() = 0; } then various subclasses of A, all implementing their good doit method. Now suppose I want to write a function that takes two iterators (one at the beginning of a sequence, the other at the end). The sequence is a sequence of A subclasses lik...