C++ :: Checking Dynamic Memory Cross-platform?
Feb 10, 2014Suppose:
cin >> number;
pointer = new type[number + (rand()%number);
So, I wont know the memory allocated for pointer. How can I check it in all OS?
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C++ :: Write Cross-platform File IO
Aug 21, 2013I discussed a topic about how to write cross-platform file IO code with a member named Disch for about a year ago. Since I am a beginner I am not sure if the "rules" for doing this has changed or not within C++.
He taught me that differenct CPU:s use different endianness when reading and writing to files. However, why can't the C++ standard file IO functions detect what endianness should be used on the current machine that is running the program? Why didn't the developers who created the standard library develop file IO functions that are cross-platform from the beginning? Have the rules changed since last year?
What I learn is that if you need to store data in files that will be read and written to on different machines, you have to define in the program what endianness should be used. For example, if I needed to store 4 bytes, I had to do this manually with my own functions and define in those which endianness is used.
C++ :: Cross Platform Way To Execute A Program?
Apr 18, 2014System();is bad, I get that. Is there another way, that works across platforms I can use to execute an external program. If not, is there a windows specific way.
View 2 Replies View RelatedVisual C++ :: Cross Platform GUI Development
Aug 28, 2013I am planning to develop a GUI that will run on Windows, Linux, Android & iOS. If am right, VC++ apps don't work on Linux, Android & iOS. Is that correct?
Is there an alternative to that? Which other tool works for GUI development on above mentioned 4 platforms?
C++ :: Cross Platform Library For Simple Dialogues
Oct 17, 2013In my game, I want to display dialogues for exceptions, and I don't really want to use something heavy like Qt, but then I also don't want to write and maintain my own platform-specific code to do it. Is there any library that can display simple message dialogues, just a few lines of text and an OK button, without being complete overkill like a full-blown GUI library?
View 13 Replies View RelatedC++ :: How To Make (compiled) Code That Other Programmers Can Use (cross-platform)
Mar 29, 2013(C++ question) I need to be able make a compiled code (like a .dll?) which other programmers can use on linux, win,, mac, etc.
The compiled code would simply do calculations and spit out an answer in memory.
I need it to have certain functions that they can easily call and understand (without actually seeing the source).
C++ :: Turn Based Game - How To Make It Cross Platform
Sep 12, 2014I am starting a turn based battle (similar to pokemon) app. How could i make this and make it cross platform. Also is it possible to make it access gps and allow other devices with the same app communicate with each other?
I have done things on the command line but i never made anything with images so i dont even know where to start for this app.
Visual C++ :: Cross Platform Program - Make A Note Of Value Of PA
Nov 4, 2013I'm working on a project which uses gtk+ and gtkmm. We use them in preference to MFC because the program needs to be cross-platform. For quite a long time, customers on OS-X and Linux have sometimes complained that the program would crash during shutdown but the Windows version (which I work on) never seemed to suffer. However, I'm now transferring my build environment to a new PC and I'm noticing the same shutdown crashes. It's a bit complicated so let me start with a small example:-
Code:
namespace Whatever {
class B {
public:
virtual ~B();
private:
int bb;
[Code] ....
Suppose I run the above program. When it stops at breakpoint #1 I make a note of the value of pA. Eventually the program reaches breakpoints #2 and #3. At each point my this pointer is exactly the same number. If the value of pA was 0x03604fb0, my this pointer is identical at both stages.
Now let's consider the real example:-
Code:
namespace Gtk {
class Widget {
public:
virtual ~Widget() {}
[Code] .....
Suppose I run the real example. At breakpoint #1 the value of pW is 0x03604fb0. But by the time I reach breakpoint #2 my this point is slightly different:- 0x03604fcc. It doesn't seem right to me and I'm wondering if it might be contributing to our shutdown crashes.
Visual C++ :: How To Determine Cross Platform Type During File Save
Nov 10, 2014I am overriding OnSaveDocument in my MFC document class to strip out the carriage returns when saving my app's document to a UNIX file system but not when the user is saving a file to a Windows file system.
Is there a way to determine if the lpszPathName in OnSaveDocument(LPCTSTR lpszPathName) is a UNIX or Windows file system?
Note, I want to avoid hard coding server names and I want to avoid overriding the FileSave dialog and forcing the user to select Windows or UNIX.
C++ :: Dynamic Memory Is Affecting Non-dynamic Values
Oct 7, 2014i'm implementing a playerclass for a game.. in the game there are multiple player types, weapons ect.. i just wanted to turn my players weapons into a dynamically allocated c_str. once i added my: Destructor, Copy Constructor and Overloaded Assignment Operator. My initial values became corrupted and i cannot fix them.
Player2.cpp
#include <string.h>
#include <iostream>
#include <cstdlib>
#include <iostream>
#include "player2.h"
#include "dice.h"
#include "gamespace.h"
[code]....
C++ :: Checking For Deallocated Memory?
Jul 20, 2014How would I go about checking for deallocated memory?
For example, let's take this into consideration:
// Unsigned 32-bit / 64-bit integer: uint32, uint64
uint32* Pointer = new uint32[ Size ];
uint64 MemAddr = ( uint64 ) Pointer;
delete[] Pointer;
The above code would proceed to create a new array, store it in a pointer and retrieve the memory address of the array before finally deleting the array.
So let's assume we re-build the pointer and try to access the now deallocated array:
Pointer = ( uint32* ) MemAddr;
Pointer[ 0 ] = 0;
Based on the above snippets of code, how would I check "Pointer" after rebuilding the memory to check if the rebuilt memory has actually been deallocated. Without a check we'd get an exception error.
A bit of detail on why I am trying this:
Before thinking up how to do this, I was storing the addresses in a list and check the list for the addresses to see if they existed or not. However this requires an O(n) search, which isn't exactly what I am wanting. So instead if I used a check for deallocation method, I can go for an O(1) time check and reduce the total time it would take to check for memory allocation/deallocation.
C :: Dynamic Memory Allocation
Jul 14, 2013I have declared a global variable as pointer. The program performs certain number of iterations. After every iteration, the size of memory required for the pointer changes and this pointer variable is to be accessed by different functions. Now, here is my doubt:If I allocate the memory for this global variable in a function, will the contents of the memory be lost once I exit that function. In my opinion, it should not be the case as the dynamic memory allocation takes place in "heap" and should not be affected by the call of functions.
View 4 Replies View RelatedC++ :: Dynamic Memory Errors
Feb 15, 2013I am new to C++ language and I am still learning.I'm doing basic stuff to better understand dynamic memory. I was wondering why I keep getting memory issues.*/
#define SIZE 15
class word {
char* str;
public:
[code]....
C++ :: Dynamic Memory Allocation (arrays)
Feb 24, 2014I have recently bought a copy of "Jumping into C++" and have come to chapter 14 ( dynamic memory location) and have a question.
On page 153-154 an example of dynamic allocation is given for array's of int. How would the code look like for strings or structs ?
The allocation was given by:
Code:
int *growArray (int* p_values, int *size)
{
*size *= 2;
int *p_new_values = new int[ *size ];
for ( int i = 0; i < *size; ++i )
{
p_new_values[ i ] = p_values[ i ];
}
delete [] p_values;
return p_new_values;
}
Sample Code I tried to use this for an array of structs but failed completely....
I used the following struct Code:
struct user{
int days;
string name;
};
and the allocation function (which does not work):
Code:
struct user *growarray (struct user *p_values, int *size) {
*size *= 2;
struct user *p_new_values = new struct user[ *size ];
for ( int i = 0; i < *size; ++i )
[Code].....
C++ :: Connect 4 Using Dynamic Memory Allocation?
Jul 3, 2013I am creating a connect 4 game using dynamic memory allocation the question is;
Write a two-player game of Connect Four where the user can set the width and height of the board and each player gets a turn to drop a token into the slot. Display the board using + for one side, x for the other, and _ to indicate blank spaces.
I have created the board. However I am unsure as how to make a start on getting the players to make moves.
Code:
#include <iostream>
using namespace std;
char **create_table(int width, int height, char blank) {
char **p_p_connect4 = new char*[height];
for(int i = 0; i < height; i++) {
p_p_connect4[i] = new char [width];
[Code]....
C++ :: Dynamic Memory Allocation In A Class
Apr 17, 2014I'm having problems with this code:
#include <iostream>
using namespace std;
class Foo {
public:
Foo( int n );// Constructor
~Foo();// Destructor
int *ptr;
int N;
[Code] ....
I'm using Visual C++ 2008 version. The problem arises at the end, after the sentence 'system("pause")' is reached, which makes me think that the problem happens when calling the destructor. The destructor is called twice, the first time it's called is in the function print. The problem seems to be that the destructor can only be called once.
I know I can avoid this situation by defining the function print like this:
void print ( const Foo &f )
...
but I would like to know if there is some way I can do this keeping the definition that I've provided.
C++ :: Freeing Dynamic Arrays From Memory
Sep 27, 2013So I'm trying to wrap my head around dynamic arrays, and I've finally figured out how to build one, using
int arraysize = randomnumber;
int* arrayname = new int[arraysize];
Now, how to delete the array. Can I free the whole array from any scope in my program using a simple line like delete arrayname;?
Also, since I'm working in heap, I can't rely on the debugger to show me when I'm doing something wrong, If I create a struct such as :
struct twoints {int one, int two};
and then try to create a dynamic array of said struct using
int arraysize = 5;
twoints* arrayname = new twoints[arraysize];
Am I basically creating an array of 5 two ints?
//is it the same as doing this?
twoints arrayname[5];
C++ :: Dynamic Memory Limit With Operator New?
May 13, 2014In my platform, Windows 7 Ultimate 64 bits with Service Pack 1 over a x86-64 AMD microprocessor, AMD Phenom II 1090T X6, with a total of 4 GBytes of RAM memory), one C++ program can only allocate up to 2 GBytes of dynamic memory (using operator new, so Heap memory).
In am using the IDE Microsoft Visual C++ 2010 Express Edition to compile my C++ program and generate the executable file (for Win32).
In my system, there are much more available memory than 2 GBytes (yet remain 1 GByte of RAM memory and the virtual memory), so, Why can't my C++ program allocate more than 2 GBytes of memory? Do I need to configure something in the IDE to allow more memory to the program?
C :: Sorting Algorithm With Dynamic Memory Allocation
Nov 17, 2013I am fairly new to dynamic memory allocation and I keep getting a segmentation fault in this code of mine. This is what the method should do:void sort StringsByReversePoints(char **myWords): This function sorts the char* values (i.e. strings) of myWords in descending order of point value by calling getWordPoints as a helper function and comparing adjacent words. This simple (but inefficient) sorting algorithm starts at the beginning of myWords array and sweeps to the end comparing adjacent values and swapping if they are out of order. After N (length of the array) sweeps the array is fully sorted. Note that efficiency can be improved by a factor of 2 by shortening each successive sweep by one, since the first sweep will have guaranteed the minimum point value word is the last element of the array, the next sweep guarantees the last two elements are correct, and so on....Additionally, if a given sweep results in zero swaps then the array is sorted and you can return immediately.
View 5 Replies View RelatedC :: Double Pointers And Dynamic Memory Allocation?
Nov 16, 2013we are currently covering double pointers and memory allocation. Currently getScrabbleWords is not working. when I compile with commented code (Main() works fine) I get a segmentation fault.
This is the purpose of getScrabbleWords:
char **getScrabbleWords(char **allWords, char letters[]):
This function takes an array of char* values (i.e. strings) representing all the words read from wordlist.txt. Each of these words is tested by callingcanWeMakeIt as a helper function, and pointers to the words that can be made are put into an array, myWords. Note, copies of the words are not made! In order to indicate the end of myWords, we terminate with a NULL pointer. Thus, if N words can be made from letters then myWords should have length N+1.
C++ :: Assign Values To A Dynamic Memory Structure?
Dec 27, 2014I create some code that assign values to a dynamic memory structure. I'm not sure why one code works and the other crashes when it assigns a value.
Working Code
#include <iostream>
using namespace std;
struct WorldOjectCollisionMap
{
[Code].....
C++ :: Why Cannot Dynamic Memory Allocation Work With References
May 5, 2013Why cant a dynamic memory allocation work with references? I was told that references work with const pointers deep down so shouldn't this be legal code?
int &&a=new int;
My compiler says that a entity of int* cannot be used to initialize a entity of int&&?
Does that mean that the compiler thinks of them as different types except deep down a reference is implemented with a pointer? Is this right?
C++ :: Pointer Incrementing Using Dynamic Memory Allocation?
Feb 13, 2013I am using a pair of pthreads that call a pair of functions for ping-pong dma data transfer that are used in a loop for data transfer from an acquisition board. For a large # of waveforms, I ultimately run out of PC memory and the program stops. At the end of each function I use the delete[] command to clear memory for reuse, but the pointer appears to advance by the array size used for the transfer until the location exceeds the 2 GB I have for memory. I can see this happening using the Task Manager performance button time plot and window of total memory used continuing to increase to the limit. The culprit for one of the functions (2nd) is:
unsigned char* dataBuffer2 = (unsigned char *) (pci_buffer2.UserAddr);
where pci_buffer1 and 2 have been set up and allocated in main. I also had the following line in each function process:
double* Rin = new double[length];
and it used up memory twice as fast. When I transferred the last line to an area just prior to main and used a constant 1024 for length, the program ran twice as far before exceeding system memory, so it appears that both lines were forcing new memory assignments and moving the pointers accordingly. In addition to using the delete[] command to free memory unsucessfuly at the end of each function procedure, I ended up closing the memory at the end of each procedure, then reallocating it again with the idea that the pointer would be set back to the original value, but it still seems to icrement along. So, neither approach appears to allow reuse of the memory because the pointer continues to march along. Using Visual C++ 6.0 to compile.
C++ :: Two Dimensional Multiplication Table - Dynamic Memory Allocation
Jun 17, 2013This is the question; Write a function that builds a two-dimensional multiplication table with arbitrary sizes for the
two dimensions.
This is what I have done. I have allowed the user to input whatever size table they want by arbitrarily choosing what value they can input. However I cannot get the board to have blank squares. I thought the char would do it.
Code: #include <iostream>
using namespace std;
char SQAURE_CHAR = {' '};
const int Board_Size = 14;
[Code] ....
C :: How To Use Malloc Or Calloc To Create Array In Dynamic Memory
Mar 10, 2014What is wrong with my function why does it spit out huge numbers? And how do i use malloc or calloc to create an array in dynamic memory, and return a pointer to this array
Code:
#include <stdio.h>#include <stdlib.h>
int fibonacci(int n)
{
int i;
long int fib[40];
fib[0]=0;
fib[1]=1;
for(i=2;i<n;i++){
fib[i] = fib[i-1] + fib[i-2];
[Code]....
C :: Dynamic Memory Allocation - Resize Array Of Pointers
May 23, 2013Suppose I wished to reallocate memory (resize) an array of pointers. Why does the following not work?(The program runs, yet yields a faulty segmentation error message. Why?):
Code: char **ptrarr = (char**) malloc(sizeof(char*))
Code: ptrarr = (char**) realloc(ptrarr, (capacity) * sizeof(char*));