std::move

std::move is a utility function that converts an object into an Rvalue Reference, enabling move semantics.

It was introduced in C++11 alongside move constructors and move assignment operators.

Purpose

• Allows you to explicitly mark an object as “safe to steal from”
• Signals the compiler that the object can transfer ownership of its resources
• Commonly used when:
  • Returning large objects from functions.
  • Moving elements into containers.
  • Implementing move constructors and move assignment operators.

When to use

Use std::move(x) when:

• You no longer need the original object x after the move.
• You want to optimize performance by avoiding unnecessary copies.
• The target type supports move semantics.

Avoid using it on:

• Variables you plan to use after
• Temporaries (They’re already rvalues)
• const objects (since they cannot be moved from, only copied).

Source Code (from `)

namespace std
{
 
template <typename T>
constexpr typename remove_reference<T>::type&& move(T&& t) noexcept
{
	using U = typename remove_reference<T>::type;
	return static_Cast<U&&>(t);
}
 
} // namespace std

How it works

• It does not actually move the object.
• It simply performs a static_cast to an rvalue reference.
• That cast allows the compiler to choose a move constructor/assignment when available.

C++ Version

• Introduced in: C++11
• Header: <utility>
• constexpr + noexcept: since C++14 and later