int NextPixel(int antIndex, int currentPixel , Ant *ant , IplImage *edgeImg) {
int left = currentPixel - 1 ;
int right = currentPixel + 1 ;
int up = currentPixel - edgeImg->widthStep ;
int down = currentPixel + edgeImg->widthStep ;
[[Code] ....
if those lines are uncommented , program gives heap error.Why?
How to add/delete object dynamically run time ?? I have a question in which i need to add/delete object dynamically dynamically how to do it ??
View 2 Replies View RelatedI have this class I have been working with,
Code:
// objects to hold results, row id, and name
class result_holder {
public:
// initialize class members
result_holder() : row_id(0), row_value(0.0), row_name("") { }
[Code] ....
There are cases where I need to find an object based on the value of row_id and delete the object from the vector row_results. I could find the proper object by looping through the vector and testing against each member.
Code:
// id I am looking for
unsigned int id_to_delete = 12;
for(i=0; i<row_results.size(); i++) {
if(id_to_delete == row_results[i].row_id) {
delete row_results[i];
}
}
I have used find before to find the position in a vector with a specific value, but I don't know how to use find to locate a specific value for an object member.
Also, is delete what I need to get rid of the object or should I be using erase as in,
Code:
// id I am looking for
unsigned int id_to_delete = 12;
for(i=0; i<row_results.size(); i++) {
if(id_to_delete == row_results[i].row_id) {
row_results.erase(row_results.begin()+i);
}
}
I have to delete an object at a time that I don't know it's held by another thread(s) or not. For example
static void foo(CLASS* ref){
pthread_mutex_lock(&l);//[POINT-A]
//using ref
//do something thread safe
pthread_mutex_unlock(&l);
delete ref;// how can I find out there is no any thread held at [POINT-A]
}
I have to manage a Clinic. I need to delete a booking (for example, if John said he's coming on March 22nd at 15:30 but then he say he's not going to come, I have to delete that booking so another person can use it).
idSearched: the id of the person that is not going to come. I have a lot of specialties and each one has a list. So I ask for the speciality to delete the node (the node contains John's booking). If I don't find it, I return (-1). searchSpecByID return a pointer to the list where the speciality is. So head will point to the first node of the list. In nodeToDelete I have the node I want to delete.
The program detects OK when is the first in the list and when not, but it doesn't delete the node.
Code:
typedef struct bookingList{
tSpecialty specialty;
struct nodo* intro;
} tList;
[Code].....
will copy constructor does object initialization using another already created object? I understand that it can be applied for object initialization and not for assignment.Is it correct?
View 10 Replies View RelatedI have a method to take a Tile object and make an instances of it based on some data from the original object. Than it is suppose to manipulate the a specific instance and save the results. The first loop through it works but it changes all instance as well as the base.
public static int recurse(int count, Tile[,] b,Huristic h,int check) {
if (check==1) {
boardState.Add(B)/>;
return check;
} if (check == 0)
[Code] .....
#include "B.h"
class A {
public :
A()
{
s_b = new B();
b = new B();
[Code] ....
In my project i have seen static object as above . But not able to know what is the exact use of it and how they are different from general object .
a function returns a temporary object like
int myfun(){
int x = 0;
return x;
}
this function will return a temporary integer now void fun1(const int & num); this function can receive from myfun().BUT void fun2(int & num); this function cannot receive from myfun() Why is that, Moreover what is lifetime of a temporary object like one returned in myfun() ???
I am trying to use web api in order to return custom json response keys. For this i have return a custom class to return json response
Custom Class:
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
[Code].....
I have a combobox with Items 1024
2048
4096
8192
String cach = form.comboCache.SelectedItem.ToString();
I am using the above code to retrive an item selected by user,But this line is giving an exception "Null Reference Exception, Object reference not set to an instance of an object"
I am using session to pass object from controller to custom class in MVC Web API. here is my code, i am getting error at session.
public HttpResponseMessage Get()
{
var person = db.Persons.ToList();
[Code]....
In Visual Studio 2010 C++
I have a series of existing text objects
The text properties names are
item1_lbl,
item2_lbl,
item3_lbl,
….
Based on a selection I want to change an object. I generate the name of the object I want to change in a string so from this string is there a way to get a pointer to the correct text object that is same name?
I'm trying to figure out how I can create a vertex array object at offset of a vertex buffer object.I've created the buffer object. I'd like the "texs" idnex data to start at the texture coordinate content of the vertex_t structure.
Type definitions:
struct vertex_t {
vector3d_t position;
float s; // Texture coordinate s
float t; // Texture coordinate t
};
Code so far:
// How do I make this start at a certain spot of the VBO?!
glVertexAttribPointer(texs, 2, GL_FLOAT, GL_FALSE, sizeof(vector3d_t), nullptr;
//...
I am beginner with C++ and I want to know. When do I use new and delete keywords? And what can I use them to do? Only thing I know about the new keyword and delete is that you can do this:
Code:
int Size = 5;
int *ptr = new int(Size);
cout << *ptr << endl;
delete ptr; And more . . .
But when do you use this keywords? I am just curios about them and want to now if them can be really effective to use.
How would I delete a row in a datagridview (and in the database) if the datagridview control does not show the primary key? ie the SELECT statement we used to load the DataGridView does not include the primary key column (since it is not relevant to the user)
View 14 Replies View RelatedMy delete is not working. Why?
Code:
struct MatchName{
MatchName(string& searchName) : s_(searchName) {}
bool operator()(const clsStudent* student) const {
return student->getName() == s_;
[Code] .....
I'm writing a sorted vector implementation and trying to do it as simply as possible.
Right now, I'm declaring the sorted vector with a protected subclass of vector, then using the "using" keyword to explicitly inherit all methods that aren't related to adding new elements to the vector (so I can control the order).
Eg:
Code: template<typename T, class Cmp = std::less<T>>
class sorted_vector : protected std::vector<T>{
public:
typedef typename std::vector<T>::iterator;
using std::vector<T>::operator=;
using std::vector<T>::assign;
using std::vector<T>::get_allocator;
using std::vector<T>::at;
using std::vector<T>::operator[];
//...
};
Obviously, this is annoyingly redundant. So what I'd like to do is something using the new "delete" keyword from C++11. Is there any quick, expressive way of deleting specific methods?
Also, it's pretty annoying to have to typedef base_class::type type to inherit a type from a base class. Is there a shorter way to do that?
here's the problem. I want to delete the objects within a vector, although I'm not sure whether I should clear the vector afterwards. Is it really necessary?
Code:
for (i = 0; i < allSales.size(); i++)
delete allSales[i];
allSales.clear(); //Is this step necessary?
How I can delete a parameter in a function .
int *buildTrail(int antIndex, int start, double *pheromones) {
int *trail = new int[tabu];
bool *visited = new bool[tabu];
trail[0] = start;
visited[start] = true;
[Code] ....
If I comment all lines includes visited word , no exception occurs , Otherwise , exception throws.
Simply put , How can i delete visited parameter as long as its role has been finished?
.
.
.
delete visited ;
return trail;
void myfuncion(){
int *a = new int[10];
int b[10];
int *p = b;
delete a
delete p
}
I cant delete b and/or p but how can i check it if i can use delete or not?
i want to check if the pointer is pointing on function temp variable ( those what gets deleted after function ends .
how to delete an element(s) from an array; suppose I have an array x[10] = {1,2,3,4,5,6,7,8,9,10}, and I want to delete array{5} so that the values of the array become {1,2,3,4,5,7,8,9,10}; how do I go about this? This is not the same as setting the value of array{5} to null; but completely eliminating it so that it does not get printed alongside the other elements of the screen.
View 3 Replies View Relatedint * ptr = new int[5];
p += 2; //p now stores address of 3rd element in array
delete [] p;
what will be deleted??? all 5 elements or just 3rd, 4th and 5th elements of array(in result making a memory leak)
I'm experimenting with a custom memory-pool for my application, and I initially planned to override the global new and delete operators to allocate memory in this pool. But since I'm using QT, this will apply to all the QT-related stuff as well. Should I instead just override the new and delete operators per class?
View 2 Replies View RelatedI have something like this:
class A {
};
class B : public A {
};
class C : public A {
};
B*b1;
B*b2;
C*c1;
C*c2;
vector<A*>vec;
int main() {
vec.push_back(b1);
vec.push_back(b2);
[Code] ....
And it don't works at all. all i get (when playing with variations of this stuff until it compiles correctlly) is a memory leak.
For example, let say i have b1 address = 1234
I will effectively free the memory at 1234, but for a strange reason, the memory leak is elsewhere, for example, at 2345, and the memory value at this address is equal to... 1234, the address of the pointer i wanted to delete.
making my delete function work. My program does compile but my delete function doesn't work. I haven't finished my last two functions because I am focusing on the delete but how to Sell a title and print the value of all sold titles would be nice as well.
#include <iostream>
#include <cstdlib>
#include <string>
[Code].....