m09-domain
Skill14 starsChanged 9 months agoMITView on GitHub
Mastering C++ Domain Modeling (DDD). Triggers: Entity, Value Object, Aggregate, Repository, Pimpl, Class Design, Invariant.
7 other projects use a version of this.
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Most recently taken up by
- TeddyAlbina/skillstheir own version, first seen Nov 1, 2026
- moeru-ai/auvtheir own version, first seen Oct 10, 2026
- fjrevoredo/mini-diariumtheir own version, first seen Oct 8, 2026
- ZhangHanDong/rust-skillstheir own version, first seen Oct 8, 2026
- MovGP0/Skillstheir own version, first seen Jun 30, 2026
- pocket-veto/pocket-vetotheir own version, first seen Jun 27, 2026
Other versions7 projects use a version of this.
Word for word · 0
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Wrote their own version · 7
- ZhangHanDong/rust-skills★ 1.5ksame name
- actionbook/rust-skills★ 1.5ksame name
- fjrevoredo/mini-diarium★ 318same name
- moeru-ai/auv★ 207same name
- TeddyAlbina/skills★ 2same name
- MovGP0/Skills★ 1same name
- pocket-veto/pocket-veto★ 1same name
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository14 other files it gives its agents.
- cpp20-skill-creatorSkill
- m01-ownershipSkill
- m02-resourceSkill
- m03-mutabilitySkill
- m04-zero-costSkill
- m05-type-drivenSkill
- m06-error-handlingSkill
- m07-concurrencySkill
- m10-performanceSkill
- m11-ecosystemSkill
- m12-lifecycleSkill
- m13-domain-errorSkill
- m14-mental-modelSkill
- m15-anti-patternSkill
The file
Files
C++ Domain Modeling
Core Question
Identity or Value?
- Value Object: Defined by attributes (
Color,Money). Equality via comparison. Copyable. - Entity: Defined by Identity (
User,Socket). Equality via ID. Non-copyable (usually).
Error → Design Question
| Issue | Design Question |
| Data Inconsistency | Are public fields allowing invalid states? |
| Object Slicing | Are you passing polymorphic Entities by Value? |
| Header Hell | Are you leaking implementation details? (Use Pimpl). |
Thinking Prompt
- Is it copyable?
- Yes? → Value Type (Rule of Zero, defaults).
- No? → Entity (Delete copy ctor, enable move).
- Does it have invariants?
- Yes? →
classwith private data + public methods. - No? →
struct(POD).
- Yes? →
- Does it own others?
- Aggregate Root? → Owns children via
std::vector/unique_ptr.
- Aggregate Root? → Owns children via
Trace Up / Down
- Trace Down:
- Intent: "User has a Name and an Address."
- Code:
class User(Entity) holdsName(Value) andAddress(Value).
Quick Reference
| Pattern | C++ Implementation |
| Value Object | struct + operator<=>. |
| Entity | class + Deleted Copy + ID field. |
| Repository | Pure Virtual Interface (virtual ... = 0). |
| Aggregate | Parent class owning children. |
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