Mastering Rust - Second Edition

Exploring the std::mem module

In regard to types and their size in memory, the mem module from the standard library provides us with convenient APIs to inspect sizes and alignment of types and functionalities for initializing raw memory. Quite a few of these functions are unsafe and must only be used when the programmer knows what they are doing. We'll restrict our exploration to these APIs:

• size_of returns the size of a type given via a generic type
• size_of_val returns the size of a value given as a reference

Being generic, these methods are meant to be called using the turbofish ::<> operator. We are not actually giving these methods a type as a parameter; we're just explicitly calling them against a type. If we were skeptical about the ...