Go Generics

This skill helps you decide when to use Go generics versus concrete types or interfaces. It walks through a clear decision flow: start concrete, generalize only when you see duplicate logic across multiple types, and prefer interfaces when shared behavior already exists. You'll find practical guidance on constraint composition with tilde and union operators, standard naming conventions for type parameters, and common pitfalls like wrapping standard library types unnecessarily or using generics just to satisfy interfaces. The advice is grounded in the Google Style Guide and emphasizes writing code first, designing types second. Most valuable when you're reaching for `any` with type switches or building reusable data structures that genuinely work across multiple types.

skills.sh installs: 1.1K
GitHub stars: 193
last updated: Aug 21, 2026

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Install

$ npx -y skills add cxuu/golang-skills --skill go-generics --agent claude-code

Installs into .claude/skills of the current project.

Files

Go Generics and Type Parameters

Compatibility: Generics require Go 1.18+.

Resource Routing

references/CONSTRAINTS.md - Read when composing constraints, using type sets, or choosing between generics and interfaces.

When to Use Generics

Start with concrete types. Generalize only when a second type appears.

Prefer Generics When

Multiple types share identical logic (sorting, filtering, map/reduce)
You would otherwise rely on any and excessive type switching
You are building a reusable data structure (concurrent-safe set, ordered map)

Avoid Generics When

Only one type is being instantiated in practice
Interfaces already model the shared behavior cleanly
The generic code is harder to read than the type-specific alternative

"Write code, don't design types." — Robert Griesemer and Ian Lance Taylor

Decision Flow

Do multiple types share identical logic?
├─ No  → Use concrete types
├─ Yes → Do they share a useful interface?
│        ├─ Yes → Use an interface
│        └─ No  → Use generics

Bad:

SKILL.md on GitHub