"Right" way to deallocate an std::vector object

Question

The first solution is:

std::vector<int> *vec = new std::vector<int>; assert(vec != NULL); // ... delete vec; 

An alternative is:

std::vector<int> v; //... vec.clear(); vec.swap(std::vector<int>(vec)); 

The second solution's a bit of a trick --- what's the "right" way to do it?

Update:

I'm aware that the destructor will be called once it's off the stack, I was curious about other methods.

Answer 1

The simplest and most reliable way to deallocate a vector is to declare it on the stack and simply do nothing.

void Foo() {   std::vector<int> v;   ... } 

C++ guarantees that the destructor of v will be called when the method executes. The destructor of std::vector will ensure any memory it allocated is freed. As long as the T type of the vector<T> has proper C++ deallocation semantics all will be well.