Questions

1. What is a good library to serialize and deserialize data?
2. What do the hashtag derive lines in front of the struct declarations in physics.rs do?
3. Which comes first in parameterized declarations—lifetimes or traits?
4. In a trait implementation, what is the difference between parameters on the impl, trait, or type?
5. What is the difference between a trait and a data class?
6. How should you declare that a package has multiple binaries?
7. How do you declare a structure field as private?