How to save vector of std::vector

new to C++

I have a question about how to save vector of ptrs.

Approach 1:

std::vector<TypeB> function(const std::vector<const TypeA*>& vector_a) {
  std::vector<const TypeB*> vector_b;

  for (const auto a : vector_a) {
    TypeB b_value = TypeB(*a);
    vector_b.emplace_back(&b_value);
  }

  return function2(vector_b);
}

Which seems only save one item.

I changed the code to: Approach 2:

std::vector<TypeB> function(const std::vector<const TypeA*>& vector_a) {
  std::vector<TypeB> vector_b;
  for (const auto& a : vector_a) {
    const TypeB value_b = EntityStateStruct(*a);
    vector_b.emplace_back(value_b);
  }

  std::vector<const TypeB*> value_b_ptr;
  for (const auto& value_b : vector_b) {
    value_b_ptr.emplace_back(&value_b);
  }

  return function2(value_b_ptr);
}

Which is working.

What I guess is in approach 1, the input const std::vector<const TypeA*>& vector_a will be destroyed when the function ends?

Need some knowledge about this part, Thank you!