Move Semantics (C++11)

Before C++11, returning a large object by value or stuffing one into a container often meant copying it byte for byte, even when the original was about to be discarded. Move semantics, added in C++11, gives the compiler a way to transfer the contents of an object that's about to die instead of duplicating them. This chapter is the conceptual introduction: what problem moves solve, when they happen automatically, and what std::move actually does. Three chapters that follow drill into the mechanics, the rvalue reference syntax, and the class-level rules.