C++ :: Pass Double Pointer Of Object Into A Node Of Self Similar Type?
Nov 30, 2014
The following code compiles and runs fine till it reaches line 16 and gets a sigsev violation which I'm not sure about as to why. I have no problem passing the object of type node** into the constructor of base and storing it into the double pointer node** copy;; but when I call the function void pass(node** temp) it crashes.
#include <iostream>
class base;
class node {
private:
node** data;
public:
Why do most C examples pass a double pointer when manipulating linkedlists? Why can not we just pass a single pointer to the struct?I think using an external reference accessor for a linked list would be a more appropriate solution, yes or no?
I got base class called Statistic and inherited classes from it : lsp, cpu, memory. Those methods inheriting some of methods from Statistic and implement also theirself methods. I prepared some new class called ExecuteRequest which is taking Statistic object in the constructor. What i want to achieve is after i put e.g LSP to this class i would like to determinate what specific object it is in this case LSP right? Then having that i would like to put this object to RunRequest method. How can i achieve that? See my code below:
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace SOAP_testing { public class ExecuteRequest
i need to pass myboard.board (board is in the class Cboard and it is an array of int) to a function in a class called piece however this is troubling . i need to pass it as pointer os that i could change its value here under is my code.
class A (abstract) class B : A class C { void add ( A(&*?) a ) std::vector<std::unique_ptr<A>> data; //unique_ptr<A> because A is abstract and therefore vector<A> isn't possible }
upper situation. What is the best way to pass add an object of class B to C?
with C::add(A* a){ vector.push_back( unique_ptr<A>(a) ); } and int main() { C c; c.add( new B() ); }
This works, but i don't think it's very nice, because you could delete the pointer in main. What happens then with the unique_ptr? I could probably make C::add( std::unique_ptr<A> u_p ); but maybe it can be avoided that the "user" (in main() ) has to create the unique_ptr itself.
I am developing a double linked list in C ( development environment ) is QT with mingw32 4.7 gcc / g++ compiler , in the header file I have defined struct as follows :
When compiling I am getting the following error : 'NODE' undeclared (first use in this function)
and
each undeclared identifier is reported only once for each function it appears in
I have also attached the screen shot from the QT IDE
look's like the compiler is not able to pick up the definition of NODE structure , same happens in Netbeans IDE , interesting thing is if change the source file from c to cpp the error goes away .
I was having problems changing the value of my head node I passed it as an argument as head which would be the address. The parameter was defined as struct node *head. like this
I tried manipultaing pointer values to change head node value but it did not work. I saw some code online which used pointer to pointers(in code below) to change head node value it worked I dont fully understand why. Would like better understanding of why.
Would also like to know why the argument call needed &head instead of just head.
remove = deleteNode(&head,found); opposed to remove = deleteNode(head,found);
I am trying this without a head/start pointer which would generally hold the address of first node. I have 3 nodes here from which I am trying to delete last node, but its not happening. I might be wrong in my logic and this is my first linked list program.
add of p1::0x9605008 add of p2::0x9605018 add of p3::0x9605028 add of p1->prev::(nil) add of p1->next::0x9605018 add of p2->prev::0x9605008 add of p2->next::0x9605028 add of p3->prev::0x9605018 add of p3->next::(nil)
no of nodes 3
enter the addresss of node to delete it 0x9605028
after deletion attempted
add of p1::0x9605028 add of p2::0x9605018 add of p3::0x9605028 add of p1->prev::0x9605018 add of p1->next::(nil) add of p2->prev::0x9605008 add of p2->next::0x9605028 add of p3->prev::0x9605018 add of p3->next::(nil)
no of nodes 3
In this example i am trying to delete the node 3 which is p3, by deleting its address 0x9605028. But after deletion the node count is still 3 and addresses are like unexpected!
const void insertStuff(const void *key, const int value){ // I want to convert the void pointer into one // of three types of pointers(int, string, or double) switch(value){ case 0: int *intPtr = key;
[Code] .....
But this causes an error of: "crosses initialization of int*intPtr"
i really don't know why has a error in my code, that pass a pointer of pointer (name of a matrix with 2 dimensions). Here is the source code of a simple example where appears segmentation fault when execute (but compiles normal):
#include <stdio.h> #define LINHAS 3 #define COLUNAS 5 float a[LINHAS][COLUNAS]; void zeros(float **p,float m, float n){ int i,j; for(i=0;i<m;i++)
I am trying to write a poker program. I created a class to create a deck of cards..and then shuffle the deck..Now I am trying to pass value from the deck to an array to deal a hand..so 5 cards to player1[] array.. I tried doing it directly such as.
But I would get error such as [Error] no match for 'operator=' in 'player1[j] = deck[j].Card::toString()'
So then I tried using a pointer..
char *getCard; getCard = new char; for (int j = 0; j < 5; j++) { getCard=deck[j].toString(); }
but I would get this error [Error] void value not ignored as it ought to be. So how can I pass a value from the object deck..to an array? or should I be doing it another way?..I tried to think of a way to do it via a function but really got hung up there..
Code: #include <stdio.h> #include <stdlib.h> int main() {
[Code].....
he problem is that when I print out the three sums at the end of the program I dont get any decimal points but just zeros like something.00 instead of something.50 etc
I am having trouble working with third party dll's, libs and header files. I am trying to call a function.here is the function that is suppose to be called.
Name IN/OUT Description m_environment IN Optional. Possible values are SANDBOX (default) and LIVE. m_strConsumerKey IN OAuth consumer key provided by E*TRADE m_strConsumerSecret IN OAuth consumer secret provided by E*TRADE m_strToken OUT Returned by the function if successful m_strTokenSecret OUT Returned by the function if successful m_strCallback IN Optional; default value is "oob"
I need to send same instance of object of a class in two function (Main function and thread function). The class is something like this:
//The class need to have constructor. Class ABC { public: DWORD *IdG; ABC(int number) { IdG = new DWORD[number]; } }obj(32);
The obj(32) is called in following two function. Function F1 is called using thread in main function.
void F1() { obj.test; } int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) { obj.test1; _beginthread(F1,0,(void*)number); }
The code works well when the object of class ABC is created as shown above. My problem is the value that is passed in the object ('32') is to be read from the file.
If I read the file and create object separately in Main function and function 'F1' then , function 'F1' is not executed.
How to create same instance of object for Main function and function 'F1' with value passed in the object taken from the file.
This all compiles ok, but the last line in the code above causes a segmentation fault. I should mention Node is declared on its own in Node.h and what pgm is. including pgm.h in node.
I'm having a bit of an issue here. I have a linked list where each node contains a pointer to a string (which has been malloc'd when the node was created and inserted) and a pointer to the next node in the linked list.
I'm creating a function which will free the node (or effectively delete it). However, I'm receiving a free(): invalid pointer error.
Can you use data type double or float for an array? ie
double n[]; or float a; float m[a];
My code wont accept me changing the data type..will on accept int data type. I get the following error when I try to change the array to double or float..
3310E:C++vector.cpp[Error] invalid types 'double [1000][double]' for array subscript
