Suppose you a class declared with a pointer initialization variable. When writing the copy constructor, how would one make a deep copy of the pointer variable? Can it be done in the same manner as automatic variables i.e. in the initialization list or in some other manner?
I am using C++ 11.
I'm trying to copy my array 'block' to a 'dummy' 3D matrix so I can take out some arbitrary smaller matrix. Shouldn't this be possible with std::copy, where I'm certain the number of elements in the 1D array are equivalent to those in the dummy?
int dummy[210][210][1000];
std::copy(&block[0], &block[block.size()], &dummy);
I have a WPF DataGrid with DataGridTemplateColumns, when I select rows and use Ctrl+C, and then in Excel or any document Ctrl+V, no data is pasted. If I change columns to DataGridTextColumn then copy and paste works fine. What can I do to make work copy & paste with DataGridTemplateColumn? Also when I set ClipboardContentBinding="{Binding FirstName}" for the template column, Null Refrence exception is thrown.
View 1 Replies View RelatedI have written this code, and at first glance it does what I want, however I am worried that
a) I am overwriting the array that is apssed from chord.getPattern()
b) Im getting a memory leak that I want to get rid of, and
c) is there generally a /what is the neater way to do it:
Code:
uint8_t* ChordBuilder::invert(uint8_t count, Chord chord) {
temp = chord.getPattern();
chord.invert(true);
//TODO count is how many times to invert. Moves root aswell however
for (uint8_t i = 0; i < count; i++){
[Code] ....
temp is a member variable of ChordBuilder - and is expressed as: Code: uint8_t* temp; I dont want the pattern that chord stores, and passes with getPattern() to change - I fear it is at the moment?
I would rather not use the "new" but I cant think how to get rid of it, however Im not sure where I would need to put the "delete"?
I want to copy over values from x to y, and its not possible as i cant use "y" as a index in my pointer array.
Code:
CellularPhoneStock::CellularPhoneStock(CellularPhoneStock &origObj){
this->phonez[nrOfPhones]->setColour = origObj.getColour();
/*this->model = origObj.model;
this->nrOfType = origObj.nrOfType;
this->price = origObj.price;*/
nrOfPhones++;
}
My questions is, how can I use origObj and phonez combined to use the function getColour() ?
Btw, phones = CellularPhone * phonez[30];
In this example code:
Code:
printf ("
Type in 1st address: ");
scanf ("%x", &address1);
address1 = (address1 - number1) * 2;
printf ("
Result = %08X
", address1);
How can i copy the contents of var address1 onto the clipboard?
Code:
HRESULT CAllocMeshHierarchy::CreateMeshContainer(PCTSTR Name,
const D3DXMESHDATA* pMeshData, const D3DXMATERIAL* pMaterials,
const D3DXEFFECTINSTANCE* pEffectInstances, DWORD NumMaterials,
const DWORD *pAdjacency, ID3DXSkinInfo* pSkinInfo,
D3DXMESHCONTAINER** ppNewMeshContainer
[Code] ....
When I make a shallow copy of pMeshData to OriginalMesh (for static mesh rendering, 2 objects pointing to one COM interface), memory leaks start to occur.When I don't, everything is fine.How to solve it? I addref() to it once (with pMeshData) and ReleaseCOM it in destroyMeshContainer
Remarks **** MeshData.pMesh is 0x00000000 while OriginalMesh is a pointer of some value whose values are 0xfeeefeee
I have this function in a class: and a private declaration: how can I copy the parameter "ProductName" to allowedProductName. I tried all combination and I can't get it to compile.
private:
StatusPanel &statusPanel;
char allowedProductName[MAX_NAME_LENGTH];
[Code].....
Is there a way to copy a derived class object thru a pointer to base?
For example:
class Base { public: Base( int x ) : x( x ) {}
private: int x; };
class Derived1 : public Base { public: Derived( int z, float f ) : Base( z ), f( f ) {}
private: float f;};
class Derived2 : public Base { public: Derived( int z, string f ) : Base( z ), f( f ) {}
[Code] ....
The question is whether *B[0] would be a Derived1 object and *B[1] a Derived2 object?If not, how could I copy a derived class thru a pointer to the base class?
I'm making a system like twitter for class called ShoutOut.com I want to be able to get the PublicShoutOut pointer pointed to by the start iterator and assign it to firstShoutOutToDisplay and secondShoutOutToDisplay because I need that in order to pass the pointers to one of my functions. When I step through the debugger the values in start are all default values like "" and so are the values in this->firstShoutOutToDisplay but the message that start points to is being output just fine.
EDIT: got rid of irrelevant code. Am I using the correct syntax to do this?
if (start != finish) {
//getting these because a shoutout needs to be passed to the function that displays
//options for a shoutout
this->firstShoutoutToDisplay = (*start);
[Code] ....
Basically I'm trying to pass an object as a reference to the template function, rather than a copy as it's seeing. I'm needing to do this without editing Obj::Call to accommodate a reference as its first parameter, as it'd break other calls.
You'll notice in the following code the object will be destroyed upon passing, while the object defined is still in-scope due to the infinite end loop.
#include <iostream>
#include <string>
using namespace std;
class Obj {
public:
string name;
Obj(string name): name(name) {cout << "create " << this << endl;}
[code]....
In the past I tried ref(), which appeared to stop this happening, however it created a blank copy of the object instead.
I have an exam in C programming I'm a little stuck on loops..I have to make a program that multiplies the loop variable by 2 then takes away 1... easy, that was a for loop no problem
for (x=3; x<=65; x=x*2-1)
that should print out 3 5 9 17 33 65 however, my lecturer has given the task for it to reverse, but not to display the number 17 on the way back down using an if statement...however, this time it must be a do while loop... This is what I have so far.
Code:
#include <stdio.h>
#include <stdlib.h>
int main()
{
int x = 129;
}
[code]....
I am wondering how I could make an array which contains arrays, but with a variable size.My first try..
Code:
int array[][] = {{1}, {2}};
But this isn't proper
what happens to pointer pt when string s is reallocated to accommodate bigger size? does it updates itself or does it points to previous s which is not used anymore?
#include <iostream>
#include <string>
using namespace std;
int main() {
string s= "aa";
[Code] ....
Should i never return a pointer to a local variable. i have seen the following code in the standard text book.
Code:
struct node *add_to_list(struct node *list, int n)
{
struct node *new_node;
new_node = malloc(sizeof(struct node));
// some code here
return new_node;
}
new_node is a local pointer then why is he returning the new_node? Is it wrong or am i failing to understand something?
I am stuck at a problem where I have two pointers pointing to the same object, and I need to change an int on one of the pointers but point to the same object.
To be more specific, there is an array of Item objects. A long list of items a player can buy. Then, there is the player's inventory, a vector pointer. Whenever a player buys an item, it sets the pointer to the bought object.
The problem arises when he buys two of the same object. I tried to identify the objects with an ID, but it does nothing, because they are just pointing to the same object, and so I have no way of telling them apart.
This is further complicated by the fact that it is a polymorphic object. So, I can't simply make a new every time I buy an object, without making a hassle. Well, at least I am not familiar with that kind of code just yet.
In the code below:
void test(int * i) {
i = new int;
*i = 10;
cout << "i: " << *i << endl;
[Code] ....
The outuput is:
i: 10
t: (some memory position).
If I really want to allocate an integer variable to t, i need to modify the void test(int * i) procedure to void test(int *& i).
I need to initialize a pointer variable with a knowing address. See code below, ptr is the final destination and value of ptr_address contains the address value, so I need to do something like ptr = *ptr_address.
Code:
int *ptr;
int *ptr_address;
int address;
address = 0x10000005;
ptr_address = &(address);
ptr = *ptr_address;
The problem is that compiler gives the following warning message:
warning: assignment makes pointer from integer without a cast [enabled by default]
Is my code wrong or there is any other way to do it without receiving this compiler warning?
I don't understand how my code not run.
#include "stdafx.h"
#include<iostream>
using namespace std;
struct student{
char name[30];
char birthday[20];
char homeness[50];
float math;
[Code] ....
this question would their be a different process if they asked "declare and initialize a pointer to the variable int cost[N][N]" Here's what I have so far
[#include<stdio.h>
int main() {
int a; // Step 1
int *ptr; // Step 2
a = cost; // Step 3
ptr = &a; // Step 4
return(0);
[Code] .....
I'm writing a delete function for a linked list, and I'm having issues with this bit of code:
void deleteNode(int data){
node* del = NULL;
t = h;
n = h;
while(n != NULL && n->_data != data){
t = n;
n = n->next;
}
}
Or more precisely, this portion:
&& n->_data != data
n is my new node variable, _data is the storage variable in the private section of my class, and data is the information being searched for that needs to be deleted. Everything works without this section of the code. My assumption is that n->_data is somehow wrong, but I don't see how. I've tried everything I can think of- using parenthesis, using the variable rather than the pointer, I've tried expressing the pointer in a different way, I've tried using my t variable rather than n, and I've found examples online that use this exact same expression without any issues.
I am having following pointer variable declaration
Code: Static double (*funcs[]) (double) = { sin,cos,tan,asin,acos};
Here funcs is an array of pointers to functions which take double as input and gives double as output with static as storage type am I right.
I am making a function that will return a pointer to a long long variable. For example, I have the next variable prototype: Code: long long funcName(long long x, int s); I want to change the return value, and the first parameter to pointers to long long.
View 4 Replies View RelatedHow can I add the variable adress to a void pointer inside of a class?
class variant2 {
private:
void *Vvariant=NULL;
public:
template<typename b>
variant & operator = (b *adress)
[Code] ....
if possible i want avoid the '&' when i assign the variable address.(variant2 f=varname;//like you see i don't use the '&')
for the moment i just need put the address to Variant pointer. but i receive several errors .
I am getting and infinite loop for loop pointer variable current which points to head and is incremented by current->next in while loop. I use the pointer variable the same way in my display routine and it works. Here is listing of code.
#include "stdafx.h"
#include<iostream>
struct node{
int data;
node *next;
[Code] .....
I'm having to do a little c++ (coming from java) and don't understand the syntax of the following declaration
Code:
SensorBase* const sensor(mSensors[i]);
It looks like it's declaring a const pointer to a SensorBase object but I don't understand how that applies to sensor(mSensors[i]) which looks like a function??