Transfer ownership within STL containers?

Question

Is it possible to transfer ownership of a vector contents from one vector to another?

vector<T> v1; 
// fill v1
vector<T> v2 = OvertakeContents(v1);
// now v1 would be empty and v2 would have all the contents of v1

It is possible for lists with splice function. This should be possible in constant time for whole vector as well.

If it isn't then why not?

Answer 1

Check out std::swap

vector<T> v1; 
// fill v1

vector<T> v2;

swap(v1, v2);
OR
v2.swap(v1);

Swap Reference

Answer 2

std::vector has a swap() function that works pretty much like this.

vector<T> v2;
v2.swap(v1);