一键在 Manus 中运行任何 Skill

m05-type-driven

星标14

分支3

更新时间2026年1月25日 07:37

Mastering C++ Type-Driven Design. Triggers: strong types, phantom types, type state pattern, builder pattern, invalid state unrepresentable.

安装

用 Codex 或 Claude 帮你安装复制这段 Prompt，粘贴到 Codex、Claude 或其他助手里，让它检查 Skill 页面并帮你完成安装。

在 Manus 中运行

来源

13eholder

13eholder/Modern-Cpp-Skills

打开 GitHub 仓库查看创作者相关仓库

下载

在 Manus 中运行

C++ Type-Driven Design

Core Question

Can I make this bug a compile error?

Primitive Obsession: Using int for IDs, double for Money. Bad.
Strong Types: struct UserId, struct Money. Good.
Type State: Connection<OFF> vs Connection<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 int unique?
- Yes? → Wrap in struct.
- struct UserId { int val; }; prevents process(OrderId).
Does valid usage depend on order?
- Yes? → Encode state in type.
- Builder::port() returns BuilderWithPort.
Are units compatible?
- No? → Template tag. Dist<Meters> + Dist<Feet>.

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`.

同仓库更多 Skills

同仓库

cpp20-skill-creator

13eholder/Modern-Cpp-Skills

Use when creating skills for C++20 standard library features, language constructs, remote third-party libraries, or local C++ projects. Keywords: create C++20 skill, create std skill C++, create concept skill, create local C++ skill, 创建 C++20 skill, 创建标准库技能, 创建 concept 技能, 本地库生成 skill, 动态 C++ skill, skill for ranges, skill for coroutines, skill for concepts, generate C++ skill from local path, C++20 技能, 从文档创建 skill, from docs create C++ skill

2026-02-1414

m01-ownership

13eholder/Modern-Cpp-Skills

Mastering C++ Ownership: Move Semantics, RAII, and Reference Safety. Triggers: std::move, use-after-free, double-free, dangling pointer, copy elision, RVO, reference qualifiers.

2026-01-2514

m02-resource

13eholder/Modern-Cpp-Skills

Mastering C++ Smart Pointers: unique_ptr, shared_ptr, weak_ptr. Triggers: memory management, cycles, enable_shared_from_this, make_unique, make_shared, custom deleters.

2026-01-2514

m03-mutability

13eholder/Modern-Cpp-Skills

Mastering C++ Const Correctness and Mutability. Triggers: const, mutable, logically const, bitwise const, data race, mutex, shared_mutex, thread safety.

2026-01-2514

m04-zero-cost

13eholder/Modern-Cpp-Skills

Mastering C++ Polymorphism: Templates, Concepts, and Virtual Functions. Triggers: templates, concepts, vtable, CRTP, static polymorphism, dynamic polymorphism, SFINAE.

2026-01-2514

m06-error-handling

13eholder/Modern-Cpp-Skills

Mastering C++ Error Handling. Triggers: exceptions, try-catch, noexcept, std::expected, std::optional, error codes, assert, terminate.

2026-01-2514

name	m05-type-driven
description	Mastering C++ Type-Driven Design. Triggers: strong types, phantom types, type state pattern, builder pattern, invalid state unrepresentable.

C++ Type-Driven Design

Core Question

Can I make this bug a compile error?

Primitive Obsession: Using int for IDs, double for Money. Bad.
Strong Types: struct UserId, struct Money. Good.
Type State: Connection<OFF> vs Connection<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 int unique?
- Yes? → Wrap in struct.
- struct UserId { int val; }; prevents process(OrderId).
Does valid usage depend on order?
- Yes? → Encode state in type.
- Builder::port() returns BuilderWithPort.
Are units compatible?
- No? → Template tag. Dist<Meters> + Dist<Feet>.

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`.