How can I realloc in C++? It seems to be missing from the language - there is new and delete but not resize!
I need it because as my program reads more data, I need to reallocate the buffer to hold it. I don't think deleteing the old pointer and…
A different question inspired the following thought:
Does std::vector have to move all the elements when it increases its capacity?
As far as I understand, the standard behaviour is for the underlying allocator to request an entire chunk of the…
What does malloc(0) return?
Would the answer be same for realloc(malloc(0),0)?
#include
#include
int main()
{
printf("%p\n", malloc(0));
printf("%p\n", realloc(malloc(0), 0));
return 0;
}
Output from Linux…
I was reading about realloc and got confused about a point mentioned there. Consider the code below:
#include
#include
int main () {
int* ptr = NULL;
ptr = realloc(ptr, 10*sizeof(int));
return 0;
}
Is there any…
I am porting a project to the iPhone and it uses realloc and memcpy which are not found. What is the header to include?
It's a project mixing Objective C and C++ and I am starting to be lost.
Thanks in advance for your help!
When we reallocate memory via realloc(), are the previous contents over-written? I am trying to make a program which reallocates memory each time we enter the data into it.
Please tell me about memory allocation via realloc, is it compiler…
I'm having troubles understanding how realloc works. If I malloc'ed a buffer and copied data to that buffer, let's say "AB":
+------------+
| A | B | \0 |
+------------+
then I realloc'ed the buffer, will there be any lost in the data (even a…
Let’s consider this very short snippet of code:
#include
int main()
{
char* a = malloc(20000);
char* b = realloc(a, 5);
free(b);
return 0;
}
After reading the man page for realloc, I was not entirely sure that the…
Simple question about the realloc function in C:
If I use realloc to shrink the memory block that a pointer is pointing to, does the "extra" memory get freed? Or does it need to be freed manually somehow?
For example, if I do
int *myPointer =…
From what is written here, new allocates in free store while malloc uses heap and the two terms often mean the same thing.
From what is written here, realloc may move the memory block to a new location. If free store and heap are two different…
In C the standard memory handling functions are malloc(), realloc() and free(). However, C++ stdlib allocators only parallel two of them: there is no reallocation function. Of course, it would not be possible to do exactly the same as realloc(),…
If realloc fails and returns NULL is the former buffer free'd or it is kept intact? I didn't found that particular piece of information in the man page and I'm quite unsure what to do. If memory is freed then double-free could be risky. If not then…
I am learning how to create dynamic 1D arrays in C. The code below tries to do the following:
Using malloc, create a dynamic array of length 10, that holds values of type double.
Set each entry of the array to j/100 for j = 0, 1,..., 9. Then print…
I have two questions.
Do realloc() and memcpy() copy the entries in an array to another in a way faster than just iterating on each element O(N) ? If the answer is yes then what do you think is its complexity ?
If the size allocated is smaller than…
How realloc work actually in the background?
If there is not enough memory available at old place does
this one allocating two/many memory blocks and one pointer
pointing to that and other are internally linked with each
other or the old region…
