使用基于范围的for循环将对象emplace_back到向量中的正确方法是什么？ C ++

Question

I have an object that I want to add it to the vector container, but I would like to know is that 2 ways I did the same thing? And what is the correct way to do it?

The reason why I did m_boid.emplace_back(std::move(bird)); is because bird is a range-based-for-loop variable and if I don't use bird it will prompt me a warning saying But program is still able to run as it's not an error.

What is the correct way to emplace_back an object into a vector using the range-based for loop?

Thank you in advance.

Boid::Boid(int size)
{
    m_boid.resize(size);  //vector of unique pointer

    for(auto &bird : m_boid)
    {
        //Create an object
        m_obj.reset(new Boid); //unique pointer

            // Add object to vector. Is this 2 below the same thing?
            m_boid.emplace_back(std::move(bird));  //Should I do this?
            m_boid.emplace_back(std::move(m_obj)); //Or should I do this?
    }
}

void Boid::initBoid(unsigned int containSize)
{

    m_boid.resize(containSize);

    for(auto &bird : m_boid)
    {
        bird.reset(new Boid);
        bird->createVAO();
    }
}

Answer 1

What is the correct way to emplace_back an object into a vector using the range-based for loop?

I'd say none. emplace_back could invalidate iterators in case of a reallocation, thus you'd get an UB in that case.