Programming :: Stl Vector As A Member Of A Struct?
Jan 17, 2011is there any problem that might rise by by having a vector as a member of struct in c++ as follows.ex.
struct A
{
int a;
[code]...
is there any problem that might rise by by having a vector as a member of struct in c++ as follows.ex.
struct A
{
int a;
[code]...
I following structure
typedef struct
{
[code]...
Is it possible to create a global struct variable with predefined member values?Only one instance of that struct is ever needed.
View 1 Replies View RelatedI have an old C application in which i am trying to include some STL cointainers. When i use the STL container alone it works fine, but when i include it into a C struct i have segmentation faults errors. I know that it is not a good idea to mix C and C++. Considering this code:
Code:
typedef struct{
int shmid;
...
APPLSPACETYPE applSpace;
[code]...
and how to make a malloc for this issue; something like :
Code:
mem->applSpace.rData.completeGroups2zeroGroup=(map_completeGroups2zeroGroup_type *)malloc((sizeof(map_completeGroups2zeroGroup_type)+1)* sizeof(char ));
Is is possible to use a class inside a struct? I keep getting segmentation fault with this code:
Code:
struct my_struct {
unsigned count;
std::string msg;
[code]....
I have been spending time (starting yesterday) reverse-engineering GTK+ to get my programming skills up. I came across a struct in the headers (_GtkArg, which was then typedeffed into GtkArg) that includes a union in it that has pretty much the same properties as a struct. Then, there was a struct inside the union.
I'm confused. Just what is the difference between a union and a struct?
P.S. I am using GTK's native C programming language.
How do we allocate memory of struct? what i did was
Code:
int main()
struct amp
{
[code].....
cout <<"The size of 'struct' is"<< sizeof(struct amp)<<"and it is located at"<<struct amp*s = malloc(sizeof(struct amp))<<endl;
it gives me an error---
In funtion 'int main()':
error: expected primary-expression before 'struct'
error: expected ';' before 'struct'
For a work project, I've got a bunch of python code from about a year ago that controls the movement of our EVI-D30 camera over a ttyUSB connection. It used to work fine on a 32-bit Fedora box, but recently we moved our whole project over to a 64-bit Gentoo server, and the same code seems to be worthless on the new platform. I didn't write the code, so I'm have trouble figuring out how to fix it. Error messages usually look like this:
Code:
File "./CameraController.py", line 172, in pan
turn_callback(cmdStruct[0], cmdStruct[1])
File "./CameraController.py", line 147, in turn_callback
cameras[camera].TiltUp()
[code]....
I having a nested structures which are referenced with pointer variables :
example :
typedef struct {
int a ;
char *b ;
int *c ;
}EXP2 ;
[Code]...
While trying to access the value of sv.exp2->a it throws segmentation fault error.How to acess this variable ??
I'm not really a C++ noob at all, but I am a little rusty at the moment. Still, I CANNOT figure out what is wrong with the following code. I'm using Visual Studio 2010.
Code: #include <iostream>
#include <fstream>
#include <vector>
#include <string>
[Code]....
I THINK I got all of the pertinent code. Anyway, it fails at the *** line. I CANNOT figure out why. If I modify it to be linein.size()-30, it STILL gives me an error. That makes zero sense.
i need to implement a Set class(like in stl) using a vector.Here is my code that doesnt work corectly:
Code:
#include <iostream>
#include <vector>
template<class T>
class Set
{
[Code]....
I have what should be a relatively simple program (fadec.c) that maps a struct from an included header file (fadec.h) to a shared memory region, but Im struggling accessing members in the struct from the pointer returned by shmat. Ultimately, I want to access members in the shared memory structure with a globally declared version of the struct, shm__. Not only do I not know how to accomplish that, but I cant even seem to access members of the shared struct directly from the pointer itself (compiler complains about dereferencing pointer to incomplete type). Im at a loss and could use another set of eyes if you guys dont mind taking a gander:
Compile Errors:
tony-pc:/cygdrive/p/test> cc -o fadec fadec.c
fadec.c: In function 'main':
fadec.c:30: error: dereferencing pointer to incomplete type
fadec.c:31: error: dereferencing pointer to incomplete type
[Code]...
int GetTime(struct timeval tv)
{
gettimeofday(&tv, NULL)
printf("%d
", tv.tv_sec); /* here is the right value */
return 0;
}
[Code]....
What happend? struct timeval has a self timer?
I am trying to simulate a shell. So what I do is checking of having the parameters from standard input, suc as "/bin/ls -l /home/france/Documents", and then passing them to function execute, which at some point calls execvp(argv[0],argv)The problem is that I don't succeed in using these arguments, while if I call execvp(paramList[0],paramList) it works!!!! Where paramList is exactly what I would put on standard input, but defined statically.
Code:
#include<unistd.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
[code].....
I have a vector of octets that needs to be converted to a std string. I'm currently doing it this way:
Code:
stringstream ss;
for (unsigned int i=0; i < data.size(); i++
{
ss << data[i];
}
string s_data = ss.str();
This works, but is there any better way to do it?
Is it not possible to declare a vector inside a C++ class ? Have a look at the following code:
Code:
#include <stdio.h>
#include <iostream>
#include <malloc.h> // malloc
#include <strings.h> // bzero
[code]....
I have two functions:
Quote:
void func1(std::string &s)
{
s.clear();
}
[code]....
Is there a way to create one template function for both vector and string that would clear them?
I am getting the following error:'auto_ptr' is not a member of 'std'This was working fine in gcc version 4.1.2 20080704 (Red Hat 4.1.2-48).After upgrading to gcc version 4.4.4 (GCC), it is NOT working.
View 2 Replies View RelatedI am trying to make a simple vector test program, but i can't compile it. Here is the code:
Code:
import java.util.*;
class Vec {
public static void main(String args [ ]) {
[Code]....
I want to read a pressed key or a combination of pressed keys from the keyboard and perform some action afterwords.
e.g.
Ctrl-Alt-F1
Out of ncurses lib. and the termios struct which can be used best for the above purpose and why ?I tried to search on Google, the differences between these two but couldn't get much !
The code below defines an array of structures in a class. I would like this to be a Static array and then initialize the array in a initialization method. I understand that initialization lists are the way to go but due to the size and complexity of the array I plan on using (the example below is a simple snippet that illustrates the problem) I would like to use the initialization method. However, I cant even get this thing to compile. The error says the reference to the ArrayOfStructs in the initialization routine is undefined.
l_long_Island
P.S. This is the error message
undefined reference to `ClassWithStaticArray::ArrayOfStruts'
class ClassWithStaticArray {
public:
struct IntegerStruct
{
[code]....
I'm making a multimedia library to speedup vector and matrix computation. But I'm getting a strange error, in this code
[Code]....
I understand that block_device pointer *bd sholuld get initialized. Program should produce initialization error for *bd. Compiler is producing '->'. I am not understanding why?
[code]...
I have added new member "i_mymember" to inode on-disk structure in ext3_fs.h file and tried to access this in userspace program, but gives me error that "error: �struct ext3_inode� has no member named �i_mymember� "
I have compiled my kernel source code.
why this error is coming ...?
I have a problem. This class is a base class for a basic enum handler:
Code:
#define ENUMOBJECT_BEGIN_ELEMENTS enum Element {
#define ENUMOBJECT_END_ELEMENTS ElementCount, DefaultElement, NoElement };
[code]...
I'm venturing into the world of OpenGL, but in the process of writing my graphics library I ran into a problem... My code is:
Code:
#include <stdio.h>
#include <stdlib.h>
[code]...
i have trouble to define a static member in a template, and i search from google, but didn't find any similar case, my case is a little complex, i paste the code below.code in xxx.h
Code:
template <class T> class FreeListManager
{
[code]...
have an inherited base class that has some virtual members and I wish to overide these members in the derived class. So for example I have the following base class called B and the derived class called D. I will illustrate them both below. I am finding I get a linker error when making the project and cannot work out why this should be so.
Code:
class B {
public:
[code]...
This for Kernel 2.6.29.6. I'm trying to code a kernel module that displays process information.
how to count opened file descriptors per task. I have been able to write a module that lists all the current process names along with their pid number in /var/log/messages. Basically, I cycle through the ring of processes using the macro for_each_process(task) and printk the comm and pid of each task. I'm trying to see how many file descriptors each task has open. I've been reading up in books and all over the internet. At first I thought I needed to access max_fds under files_struct, but that just lists the maximum number of file descriptors that can be opened per task, which by default is set at 256. I then thought about counting the elements in the fd_array. But then I learned that every task's fd_array is initially set at 32. Now I know that I need to access open_fds of type fd_set * in files_struct. open_fds is a pointer to all the open file descriptors. The problem is that I don't know how to access a pointer of type fd_set.
Is there a good guide or book that really focuses on type fd_set and open_fds? Every book and resource I've read never really go into depth on this. relationship between files struct, open_fds, and the open file descriptors in task?
I'm trying to write some code that involves creating a function to return a vector iterator.I'm not sure what is wrong.
Code:
template <typename T> class VectorTemplate
{
[code]....