I am working on this project where I need a function to be called every second. At this time, I am thinking that I have to create a thread but I am clueless on how it will get called every second.
View 5 RepliesOk so I am working on a game and I'm in the process of developing my Player class. Anyways, what I have is a keyboard function that is called in my main function to make a shape move.
void myKeyboardFunction(unsigned char key, int x, int y) {
switch ( key ) {
[Code].....
But when I try to call it, trying to copy my previous method,
glutKeyboardFunc(Player1.playerControls);
I get an error
error C3867: 'Player::playerControls': function call missing argument list; use '&Player::playerControls' to create a pointer to member
I get an error saying it can't convert parameters. I would just like to understand why the arguments become a problem when I make the function a member of my class, when the first method I used is so easy.
I am new to C and trying to reverse a string but the function is not getting called.. the console says :
Enter a stringabhi
bash: line 1: 229 Segmentation fault (core dumped) ./program
Code:
#include<stdio.h>
#include<math.h>
#include<string.h>
char* reverseString(char input[]);
void main()
[Code] ....
Here are the classes:
BaseClass.h
Code:
class BaseClass {
public:
BaseClass();
virtual ~BaseClass();
virtual void printStuff() const;
[Code] ....
When I call printStuff, the DerivedClass's function gets called. Now, if I remove the const part from the DerivedClass's printStuff function, we call the BaseClass's printStuff function.
There is already a thread with exactly the same problem I have, but the answer to solve the problem isn't stated at the end. Problem with callback as classmember.
View 4 Replies View RelatedAs I am taking my first steps in C, I study K&R (I guess most of you did the same, right?)
In the introductory chapter about functions (1.7) there is an example showing how to create a function that is then called to calculate powers (b**n). I simplified it to calculate only one given power, 2**5:
Code:
#include <stdio.h>
int power(int m, int n);
main() {
printf("%d", power(2,5));
[Code]....
It will then be called to make the calculation in the above string.
First things first: we already know how to use while(getchar!=EOF) to count characters (K&R chapter 1.5.2) but what if -instead- the input is a specific string? How to "read" it and how to tell my program that the string is finished? And most important: "reading" will be done in the function or in the rest of the body?
So on lines 36 - 39 (The commented out functions) is where I'm sure is causing this error because once I don't comment them out pretty much everywhere Flink or Rlink is used or defined I get this error.
#ifndef nodes_Nodes_h
#define nodes_Nodes_h
#include <cstdlib>
[Code]....
How to find the size of an array in called function? When we pass the array a argument to function definition we will be having base address of array, so my understanding is that we will not get the size of an array? but is there any hacking for this to find size of array other than passing as size an argument to this called function?
View 3 Replies View RelatedWrite a recursive function called sumover that has one argument n which is an unsigned integer. the function returns double value which is the sum of reciprocals of the first n positive integers =.
for example sumover 1 returns 1.0
sumover 2 returns 1.5 like 1/1+1/2
I'm currently making a game and what happens is that during runtime, it suddenly closes and a message is shown in the console saying "Pure virtual function called at runtime".
Here is the code: [URL]
The problem seems to occur somewhere between lines 662 - 695. And it seems to only happen when the size of the vector reaches 1.
I have a function and i want to delete a file when the function is called and starts it's loop i have used this code but unfortunately the file is not deleted ?
Code:
void evaluate(void) /*evaluate the population */{
int mem;
int i;
double x[NVARS+1];
char buffer[101] = {"save.txt"};
[Code] .....
Is there anyway we can return 2 values from a called function. Example
Code:
float xxxx(float a, float b, float c, float d)
{///
///
///
}
void xxx() {
int e,f,g,h;
////
////
xxx(e,f,g,h);
}
So if I want for example a+b and c+d, can i return those 2 answer? I don't think its possible since I am new into C programming.
My program seems to be working fine, except for when I call on my delete function. I don't receive any errors, but when I call the delete function my program outputs nothing and freezes. As in, my print function (which is called before the delete function) doesn't even work. I've tried removing bits of the function to see if I could pinpoint where exactly the issue is, but I've had no luck.
#include <iostream>
#include <string>
using namespace std;
class List{
private:
struct node{
string _data;
[Code] ....
And the function that is causing me trouble:
void deleteNode(string data){
node* del = NULL;
t = h;
n = h;
while(n != NULL && n->_data != data){
[Code] .....
I've created a function where you can choose any bounds for an array based list (positive or negative, as long as the first position is smaller than the last position). However for some reason when I call the print() function in my application program it doesn't do anything. My print function is technically correct (I still have work to do on the output) but I can't figure out why it wont show anything at all. Below is my header, implementation, and main program files, along with results from running the program.
Header File:
//safearrayType Header File
class safeArrayType {
public:
void print() const;
void insertAt(int location, const int& insertItem);
safeArrayType(int firstPlace=0, int maxPlace = 100);
[Code] ....
ResultsEnter the first bound of yourlist: -3(this was my input)
Enter the last bound of yourlist: 7(this was my input)
Press any key to continue...
I have a function in one src file called from code in a different src file.
In ig_cfunc.cpp
Code:
#include "ig_tools.h"
int x2_count = 0.0;
float rel_branch_degree_tmp = 0.0;
string type;
vector<int> is_disp_type;
[Code] ....
I am getting a linker error,
Code:
ig_cfunc.cpp:1609: error: `calc_rel_branch_degree' undeclared (first use this function)
I have deleted all of the objects and recompiled to make sure that everything is in sync. I can't see what the issue is here and I'm not sure what to do next. This code actually worked until I changed the name of the function, so the types are all correct and such. This is the format I use for all external functions ....
consider this code:
Code:
private void DoIf(bool b, Action f)
{
if (b)
f();
}
int x = 0;
bool no = false;
DoIf(no, () => x = 10);
Does the compiler emit code to create a new action when the function is called or only when f() is actually called?
#include <iostream>
class Hello {
public:
void Test() {
[Code].....
As i know a non-constant member function cant be called inside a constant member function but how the above code has been compiled successfully and giving the expected result .
The following are the cases when copy constructor is called.
1)When instantiating one object and initializing it with values from another object.
2)When passing an object by value.
3)When an object is returned from a function by value.
I don't understand #2 How can and object be passed by value? when I think of passing object I think of passing by address or reference. explain
I don't understand #3 how can a function returned object by value I think of again passing by address or reference.
Why in this code the destructor is called 2 time? How can i avoid it?
int _tmain(int argc, _TCHAR* argv[]) {
Elenco e1;
std::cout << "Test 2" <<std::endl;
std::cout<<e1.size()<<std::endl;
[Code] ....
Whenever my copy constructor is called, my destructor destroys is immediately after.
My copy constructor
CS1CStudent::CS1CStudent(const CS1CStudent& otherCS1CStudent)
{
cout << "
***************************
";
[Code]....
The copy constructor is called twice, once when you pass an object by value, and once when the object is returned from a function by value. But why is the destructor being called twice?
"Destructors for a derived class object are called in the reverse order of the constructors for the object. This is a general rule that always applies. Constructors are invoked starting with the base class constructor and then the derived class constructor, whereas the destructor for the derived class is called first when an object is destroyed, followed by the base class destructor."
But why, or is it just because, so programmers know which one and modify their destructor accordingly??
In this code:
#pragma once
#include <iostream>
class CBox // Derived class {
public:
// Constructor
explicit CBox(double lv = 1.0, double wv = 1.0, double hv = 1.0) : m_Length(lv), m_Width(wv), m_Height(hv){}
[Code] .....
Before the program ends, at return 0;
I would expect the CBox destructor to be called 3 times but it is being called 6 times? Why? Also in this code:
#pragma once
#include <iostream>
class CBox // Derived class {
public:
// Constructor
explicit CBox(double lv = 1.0, double wv = 1.0, double hv = 1.0) : m_Length(lv), m_Width(wv), m_Height(hv){}
[Code] .....
Why is the destructor called 3 times? When have you really destroyed a CBox? Doesnt emplace only create it and store it, then thats it?
[URL] .....
For pushback:
void push_back(value_type&& _Val)
{// insert by moving into element at end
if (_Inside(_STD addressof(_Val)))
{// push back an element
size_type _Idx = _STD addressof(_Val) - this->_Myfirst;
[Code] .....
I was trying some virtual mechanism then This came to my mind
#include <iostream>
using namespace std;
class A
{
[Code].....
now My concerns is that though the function f() in B was private it gets called by the pointer of class A as it is a virtual function
so is this a violation of access control?
OgreWidget.h
Code:
#ifndef __OGREWIDGET_H__
#define __OGREWIDGET_H__
#include <OGRE/Ogre.h>
#include <QGLWidget>
//#include <QX11Info>
class OgreWidget : public QGLWidget {
//Q_OBJECT;
[Code] ....
The inherited method called createScene is not called.
I was wondering that why in the below code, the copy constructor is called 2 times.
Code:
class A {
private:
static int count;
int age;
public:
A()
[code].....
I think that when f(a) is called, since I am passing this as value, no copy constructor should be called. The copy constructor should called when the return object "x" is assigned to:
A b = x;
why copy constructor called 2 times?
I would like to know how could I make multiplication of matrix called betrix in this code:
Code:
printf("transposed matrix:
");
int trantrix[size][size]; //transposed matrix
for(i=0;i<size;i++) {
for(j=0;j<size;j++) {
trantrix[i][j] = matrix[j][i];
printf("%d ",trantrix[i][j]);
[Code] ......