Day 23: Derive Macros

Derive macros automatically implement traits for your types - a huge productivity boost!

Common Derivable Traits

#[derive(Debug, Clone, PartialEq, Eq, Hash, Default)]
struct User {
    name: String,
    age: u32,
}

Trait	Purpose
`Debug`	Enables `{:?}` formatting
`Clone`	Enables `.clone()` method
`Copy`	Implicit copying (for simple types)
`PartialEq`	Enables `==` comparison
`Eq`	Marker for full equality
`Hash`	Enables use as HashMap key
`Default`	Enables `Type::default()`
`PartialOrd`	Enables `<`, `>` comparison
`Ord`	Full ordering

Solana Relevance: In Anchor, you'll frequently use:

#[derive(AnchorSerialize, AnchorDeserialize, Clone)]
pub struct TokenAccount { ... }

Debug Trait

#[derive(Debug)]
struct Point { x: i32, y: i32 }

let p = Point { x: 1, y: 2 };
println!("{:?}", p);   // Point { x: 1, y: 2 }
println!("{:#?}", p);  // Pretty-printed

Clone vs Copy

#[derive(Clone, Copy)]  // Copy requires Clone
struct Point { x: i32, y: i32 }

let p1 = Point { x: 1, y: 2 };
let p2 = p1;  // Copy happens automatically
// p1 is still valid!

Copy can only be derived for types whose fields are all Copy. Types with heap data (like String) cannot be Copy.

The Task

Add the necessary derive macros to make the code compile:

Debug for {:?} printing
Clone for .clone()
PartialEq for == comparison

Requirements

Print the token with {:?}
Compare two tokens with ==
Clone works correctly

Hints

#[derive(Debug, Clone, PartialEq)]
struct Token {
    symbol: String,
    amount: u64,
}