What is faster and/or generally better? vector<myType> myVec; int i; myType current; for( i = 0; i < 1000000; i ++ ) { current = myVec[ i ]; doSomethingWith( current ); doAlotMoreWith( current ); messAroundWith( current ); checkSomeValuesOf( current ); } or vector<myType> myVec; int i; for( i = 0; i < 1000000; i ++ ) { doSome...
Based on the following question: Check if one string is a rotation of other string I was thinking of making a cyclic iterator type that takes a range, and would be able to solve the above problem like so: std::string s1 = "abc" ; std::string s2 = "bca" ; std::size_t n = 2; // number of cycles cyclic_iterator it(s2.begin(),s2.end(),n); ...
I'm doing my first C++ - Qt4 application and I'm having some trouble "connecting" my different uis. I have a main window with several buttons and when I click on one, I want another window to open. The MyMainWindowClass inherits from QMainWindow and the other from QWidget. Here is the code I have written so far : #include <iostream>...
#include <stack> using namespace std; int main() { stack<int> s; int i; for (i = 0; i <= 10; i++) { s.push(i); } for (i = 0; i <= 10; i++) { printf("%d", s.pop()); } } Whats wrong with the code above? Error: In function int main(): aggregate value used where an integer was expected ...
Assume that int array arrayName is a member of class className, How can I access its element in my main program?? className.arrayName[0] doesn't seem to work ...
Since the function template in the following code is a member of a class template, it can't be specialized without specializing the enclosing class. But if the compiler's full optimizations are on (assume Visual Studio 2010), will the if-else-statement in the following code get optimized out? And if it does, wouldn't it mean that for ...
I have a struct: //Custom packet structure. struct UserPacket { __int64 pingTime; } CustomPacket; I have already figured out how to convert it to a char*. Now I want to convert the char* back to the struct. Any suggestions? ...
How do I print coloured characters to a Linux terminal that supports it? I'm using C++ for this program, but I think that might be irrelevant. EDIT: And secondly, how do I tell if it supports colour codes? ...
#include<string> ... string in; //How do I store a string from stdin to in? // //gets(in) - 16 cannot convert `std::string' to `char*' for argument `1' to //char* gets (char*)' // //scanf("%s",in) also gives some weird error Similarly, how do I write out in to stdout or to a file?? ...
Hello, I need in analyzing system output sound runtime. OS: Linux. The first thing I need is get different frequency values. Programming language: c++. ...
Do I have to put code from .cpp in a namespace from corresponding .h or it's enough to just write using declaration? //file .h namespace a { /*interface*/ class my { }; } //file .cpp using a::my; // Can I just write in this file this declaration and // after that start to write implementation, or // should ...
Our lecturer has given us a task,I've attempted it and try every single effort I can,but I still struggle with one of the problem in it,here goes the question: The company you work at receives a monthly report in a text format. The report contains the following information. • Department Name • Head of Department Name • Month • Minimum ...
Below program contains two show() functions in parent and child classes, but first show() function takes FLOAT argument and second show() function takes INT argument. .If I call show(10.1234) function by passing float argument, it should call class A's show(float a) function , but it calls class B's show(int b). #include<iostream> usin...
HI I am writing a part of a server which should dispatch some other child processes. Because I want to wait on some of the processes, and dispatch others without waiting for completion, I use double fork for the second kind of processes (thus avoiding the zombie processes). Problem is, my server holds a lot of memory, so forking takes a ...
Hi, I am using JNI to call my C++ function from Java. One of the C++ function's arguments is jobject thiz (as far as I know, all JNI native functions have this argument). The function takes quite long to complete and I want to report progress back to the jobject thiz Java object, so that I can show the progress to the user. How can I cal...
Does anyone have any suggestions for a good cross platform input library? I'd like to get: * at least keyboard and mouse input * on at least the big three operating systems * Small/fast * C or C++ * permissive licensing gpl2/mit/free/etc. So far I've seen: * OIS (used in Ogre) http://sourceforge.net/projects/wgois/ * SDL (used everyw...
I'm looking for a streaming xml pretty printer for C/C++ that's either self contained or that uses libxml2 or expat and has a BSD-ish license. I've searched a bit and not found one. It seems like something that would be generally useful. Am I missing an obvious tool that does this? Background: I have a library that outputs xml without w...
I'm writing a program, foo, in C++. It's typically invoked on the command line like this: foo *.txt My main() receives the arguments in the normal way. On many systems, argv[1] is literally *.txt, and I have to call system routines to do the wildcard expansion. On Unix systems, however, the shell expands the wildcard before invokin...
What is the problem with the last two statements in the code? #include <iostream> using namespace std; int main() { cout << "2 + 4 = " << 2 + 4 << endl; cout << "2 * 4 = " << 2 * 4 << endl; cout << "2 | 4 = " << 2 | 4 << endl; cout << "2 & 4 = " << 2 & 4 << endl; What should I do to fix this? ...
I am trying to use windows dll functionality in Linux. My current solution is a compilation of a separate wine application, that uses dll and transfer requests/responses between dll and main application over IPC. This works, but is a real overhead comparing to a simple dll calls. I see that wine-compiled program usually is a bootstrapp...