Question

vector< int > vect;
int *int_ptr = new int(10);
vect.push_back( *int_ptr );

I under stand that every “new” needs to be followed by a “delete” at some point but does the clear() method clean this memory?

What about this method of doing the same thing:

vector< int > vect;
int int_var = 10;
vect.push_back( int_var );

From what I understand, clear() calls the variables destructors, but both vect.push_back() methods in this example push an object on the vector, not a pointer. so does the first example using an int pointer need something other than clear() to clean up memory?

Answer 1

The first method leaks because the vector never takes ownership of the allocated pointer. In fact, it doesn’t contain a pointer at all, only a copy of the value.

The second method does not leak, as no memory is dynamically allocated (except internally in the vector — it will handle that memory itself).