# struct (0-struct.org)

A struct is a thing that holds other things together. In everyday talk, it is short for structure: a building, a framework, or any organized setup.

## What a model may hear
- C struct (C, C++, and systems programming): Expect a fixed block of named fields in memory, and may write or read code that treats data as a packed binary layout
- Rust struct (Rust): Expect an owned or borrowed composite type with named fields, and may suggest ownership patterns, lifetimes, or derive macros
- Go struct (Go): Expect a value type with methods attached, and may assume struct embedding or interface satisfaction is relevant
- protocol struct (networking and serialization): Expect a fixed packet or message format, and may propose binary layouts for wire formats like protobuf or capnp
- data structure (computer science broadly): Generalize to any organized collection of data, and may discuss algorithms for trees, graphs, or hash tables

## Where people and models part ways
- Says: "Give me a struct for my team"
  Means: I want an organizational chart or team structure
  May be taken as: The model writes a C or Go code block defining a struct type with employee fields
  Say instead: "Give me an organizational chart for my team"
- Says: "How do I build a struct for this?"
  Means: How do I design the overall framework or plan?
  May be taken as: The model gives programming syntax for defining a composite data type
  Say instead: "How do I design the overall framework for this project?"
- Says: "The struct is falling apart"
  Means: The building or organization is failing
  May be taken as: The model debugs memory alignment or field layout in a data structure
  Say instead: "The organization or building is falling apart"
- Says: "I need a struct with flexible members"
  Means: I need an adaptable organization or framework
  May be taken as: The model explains C flexible array members or Rust generic structs
  Say instead: "I need a flexible framework or adaptable organization"

## Tips
- Say 'data structure' only when you mean a programming concept, or 'structure' for the everyday sense
- If you want code, name the language: 'a C struct', 'a Rust struct'
- Avoid 'struct' alone when asking about organizations, buildings, or plans
- If the model offers code you did not want, say 'I meant the general concept, not programming'
- Use 'layout' or 'schema' if you need a model to think about shape without assuming a specific language

## Often confused with
- class: implies inheritance and methods, not just grouped data
- record: often implies immutability or database rows
- tuple: unnamed fields, ordered by position
- interface: behavior contract without data storage
- union: overlapping memory, one field active at a time
- schema: describes shape without fixing memory layout