smart pointers and arrays
C++C++11Smart PointersC++ Problem Overview
How do smart pointers handle arrays? For example,
void function(void)
{
std::unique_ptr<int> my_array(new int[5]);
}
When my_array
goes out of scope and gets destructed, does the entire integer array get re-claimed? Is only the first element of the array reclaimed? Or is there something else going on (such as undefined behavior)?
C++ Solutions
Solution 1 - C++
It will call delete[]
and hence the entire array will be reclaimed but I believe you need to indicate that you are using an array form of unique_ptr
by:
std::unique_ptr<int[]> my_array(new int[5]);
This is called as Partial Specialization of the unique_ptr
.
Solution 2 - C++
Edit: This answer was wrong, as explained by the comments below. Here's what I originally said:
> I don't think std::unique_ptr knows to call delete[]. It effectively > has an int* as a member -- when you delete an int* it's going to > delete the entire array, so in this case you're fine. > > The only purpose of the delete[] as opposed to a normal delete is that > it calls the destructors of each element in the array. For primitive > types it doesn't matter.
I'm leaving it here because I learned something -- hope others will too.