pointers Questions
2
Solved
There is a strange behavior of lobstr::obj_addr caused by its vectorization over lists, when the list itself doesn't change the address.
I just started Advanced R by Wickham (2ed) and reached the 2...
Brambling asked 16/9 at 16:19
6
Solved
I have a char array that is really used as a byte array and not for storing text. In the array, there are two specific bytes that represent a numeric value that I need to store into an unsigned int...
3
I know how to get the value of a variable by its id in Python like:
a = "hello world!"
ctypes.cast(id(a), ctypes.py_object).value
I wonder if it possible to overwrite the variables value by id?
...
4
Solved
Let's say that I have a main class SomeManager for keeping track of instances of another class SomeClass. When SomeClass is constructed it calls a method of SomeManager passing a pointer to itself....
Snow asked 13/2, 2015 at 4:8
3
There are three ways to pass an array to a function
1.
void changeArray(int array[]) {
array[0] = 1111;
}
void changeArrayByPointer(int * array) {
array[0] = 1111;
}
void changeArray(int ...
8
Solved
Are array of pointers to different types possible in c++?
with example please)
3
Solved
I'm implementing an A* pathfinding algorithm in C++ to solve a maze, but I'm encountering a segmentation fault (SIGSEGV) when the maze size is high (~10,000x10,000 or larger).
The error occurs in ...
Ringed asked 8/8 at 14:16
3
Solved
I have a function that is used to allocate a buffer with given size. The buffer will be preprocess/filled some data before return. This preprocess may return false to represent this buffer is not p...
China asked 22/10, 2015 at 6:48
6
Solved
I think this is a really easy thing to code, but I'm having trouble with the syntax in C, I've just programmed in C++.
#include <stdio.h>
#include <stdlib.h>
void pointerFuncA(int* ip...
4
Solved
In C one can have string literals in the form of
char *string = "string here";
integer literals:
uint8_t num = 5;
long literals:
long long bigNum = 90322L;
floating point literals:
float...
6
Solved
Does a std::map where the key is a pointer dereference pointers, or do you need a custom comparator?
I have a question on how pointers to a custom object are handled when used as Keys in an map. More specifically if I define
std::map< CustomClass*, int > foo;
Would the default C++ implem...
Recalcitrate asked 4/8, 2014 at 16:6
2
The C Standard defines lvalue as:
An lvalue is an expression (with an object type other than void) that potentially designates an object;64) if an lvalue does not designate an object when it is ev...
Accommodation asked 27/6 at 6:16
3
Solved
In this answer to this question, it was noted that:
If you're going to 'clear' the pointer in the dtor, a different idiom would be better - set the pointer to a known bad pointer value.
and also ...
Macneil asked 24/6 at 19:23
4
Solved
I have this:
vector<Object*> myVec;
and adding my objects to it like this:
Object *obj1 = new Object;
myVec.push_back(obj1);
Let's assume that I have 100 objects in this way and pointer...
9
Solved
I have looked around but have been unable to find a solution to what must be a well asked question.
Here is the code I have:
#include <stdlib.h>
struct my_struct {
int n;
char s[]
};
in...
Seymour asked 13/1, 2010 at 23:2
3
Solved
I was hitting an issue in a project I'm working on. I found a way around it, but I wasn't sure why my solution worked. I'm hoping that someone more experience with how Go pointers work could help m...
5
Solved
typedef char* c;
const c ptr1 = "pointer";
++ptr1; /// error
const char* ptr2 = "pointer";
++ptr2; /// runs fine
Now ptr1 should be of type const char* and thus a non-const pointer, then why is i...
6
Solved
It's fairly common knowledge that if you access an element of an array as arr[i] in C that you can also access the element as i[arr], because these just boil down to *(arr + i) and addition is comm...
Million asked 24/8, 2011 at 19:58
5
I would like to call C functions (e.g. form the stdlib, math ...) dynamically. This means that my C program only knows the pointer to a random function (e.g. printf) and its signature (coded as a c...
5
Solved
I thought I've read somewhere that when using pointers and we want to copy the content of one to another that there are two options:
using memcpy or
just assigning them with = ?
However in the ...
1
Solved
Can I declare a C pointer with an intialization to its own address?
void* p = &p;
I am specifically concerned with if this is strictly standard compliant in C23 (as the draft currently stands)....
Coelostat asked 6/4 at 4:34
20
Solved
Can we check whether a pointer passed to a function is allocated with memory or not in C?
I have wriiten my own function in C which accepts a character pointer - buf [pointer to a buffer] and size...
24
Solved
I'm coming from a Java background and have started working with objects in C++. But one thing that occurred to me is that people often use pointers to objects rather than the objects themselves, fo...
7
Solved
I am little bit confused about pointers and how many bytes they take up. In my textbook it first says that pointers on 16 bit systems take up 2 bytes, 32 bit systems 4 bytes, 64 bit system 8 bytes ...
5
Solved
Edit: Thanks, amazing help, as always :)
I can't find the solution to this, I have an unique_ptr to a base class, that has the data of a derived class, and I want to set it's type to the derived c...
Phineas asked 11/11, 2015 at 11:24
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