c++ assignment deletes source of assigned value

I have a class (simplified):

class a {
  private:
    std::vector<a> arguments;
  public:
    std::vector<a> getargs() { return arguments; }
};

Suppose, the class has a member function:

void a::bubble() {
  arguments = arguments[0].getargs();
}

Is this kosher (in that the source of the data, arguments[0], is deleted as a result of the command)?

开发者_JS百科

It works on my compiler, but I just wanted to check if the c++ standard guarantees the safety of this operation.

---

Yes, it is ok. The getargs() function is done before the assignment. It creates a temporary that exists for the lifetime of the complete instruction statement (everything to ;). That temporary is used in the call to the assignment operator for std::vector (works for raw types too though). Everything is kosher and will work just fine.

---

Why wouldn't it be legal? Of course you will still go to the programmer's hell for this, but then again it's not really you, it's C++.

---

I've no idea what do you want to do, but it should work fine. The only problem is that you must to be sure that you have at least 1 element in arguments.