Mastering Rust - Second Edition

Move and copy semantics

In Rust, variable bindings have move semantics by default. But what does this really mean? To understand that, we need to think about how variables are used in a program. We create values or resources and assign them to variables to easily refer to them later in our program. These variables are names that point to the memory location where the value resides. Now, operations with variables such as reading, assignment, addition, passing them to functions, and so on can have different semantics or meaning around how the value being pointed to by the variable is accessed. In statically typed languages, these semantics are broadly classified as move semantics and copy semantics. Let's define both.

Move semantics: A value ...