m05-type-driven
Skill14 starsChanged 9 months agoMITView on GitHub
Mastering C++ Type-Driven Design. Triggers: strong types, phantom types, type state pattern, builder pattern, invalid state unrepresentable.
7 other projects use a version of this.
Adopted by
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
None found.
Edited · 0
None found.
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
- m06-error-handlingSkill
- m07-concurrencySkill
- m09-domainSkill
- m10-performanceSkill
- m11-ecosystemSkill
- m12-lifecycleSkill
- m13-domain-errorSkill
- m14-mental-modelSkill
- m15-anti-patternSkill
The file
Files
C++ Type-Driven Design
Core Question
Can I make this bug a compile error?
- Primitive Obsession: Using
intfor IDs,doublefor Money. Bad. - Strong Types:
struct UserId,struct Money. Good. - Type State:
Connection<OFF>vsConnection<ON>.
Error → Design Question
| Issue | Design Question |
| Swapped arguments | Did you pass width to height? (Use Strong Types). |
| Invalid State | Did you call read() on closed file? (Use Type State). |
| Unit confusion | Did you mix Meters and Feet? (Use std::chrono style units). |
Thinking Prompt
- Is this
intunique?- Yes? → Wrap in
struct. struct UserId { int val; };preventsprocess(OrderId).
- Yes? → Wrap in
- Does valid usage depend on order?
- Yes? → Encode state in type.
Builder::port()returnsBuilderWithPort.
- Are units compatible?
- No? → Template tag.
Dist<Meters>+Dist<Feet>.
- No? → Template tag.
Trace Up / Down
- Trace Up:
- Issue: "Rocket crashed because of Metric vs Imperial confusion."
- Cause:
double calculate_trajectory(double dist)accepted any number. - Fix:
Dist<Meters> calculate(Dist<Meters> d). Compilation fails if you pass Feet.
- Trace Down:
- Intent: "Ensure file is open before reading."
- Code:
File<Open> f = File<Closed>().open(); f.read();
Quick Reference
| Pattern | Cost | Use When |
| Struct Wrapper | Zero | Distinct IDs, coordinates. |
| Enum Class | Zero | Type-safe flags (no implicit int conv). |
| Phantom Type | Zero | Tracking state without storage. |
| User Literal | Zero | 10_m, 50_s. |
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
No reviews yet
People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.
- It worked
- Partly
- It didn't
Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.
Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.