Write Powerful Rust Macros

4 Making fields public with attribute macros

This chapter covers

• Understanding the differences between derive macros and attribute macros
• Finding field information in the abstract syntax tree
• Retrieving fields by using matching
• Retrieving fields with a custom struct
• Retrieving fields with a custom struct and a Parse implementation
• Adding multiple outputs in quote
• Debugging macros with log statements
• Understanding the no-panic crate

Rust likes to hide information. A function, struct, or enum is private by default, and the same goes for the fields of a struct. This is very sensible, though occasionally slightly annoying when you have a struct that has a lot of fields that are better off being public. Data Transfer Objects (DTOs) are a ...