std::move Vs std::forward

Question

This seems to be most relavant question already asked.

Whats the difference between std::move and std::forward

But each answer is different and applies and says

Answer 1

In this case:

void push_back(T&& value)
{
     resizeIfRequired();
     moveBackInternal(std::forward<T>(value));  // (1)             
     moveBackInternal(std::move(value));        // (2) 

}

std::forward<T>(value) and std::move(value) are identical in this scenario (it doesn't matter between (1) and (2)... so use (2)).

move is an unconditional cast to xvalue. That line gives you an expression of type T&& that's an rvalue, always.

forward is a conditional cast. If T is an lvalue reference type, it yields an lvalue. Otherwise (if it's either not a reference type or an rvalue reference type), it yields an rvalue. In our case, T is not a reference type - so we get an rvalue.

Either way, we end up at the same point - we call moveBackInternal with value cast as an rvalue. Just move() is a simpler way of getting there. forward<T> works, but it's unnecessary.