Optimistic Peach questions

Optimistic Peach answers

• Why does switching from struct to enum breaks API, exactly?
• When should I use smart pointers?
• Returning a trait with an associated type
• What to use for covariance over fn parameter in Rust?
• How do I annotate rust variables' data type without assignment?
• Understanding `tt` in Rust's `macro_rules!` macros
• Why must be structure initialized in rust?
• Storing a module as a variable in rust
• How are sized types useful in Rust?
• How to implement fmt::Display on custom type?