Generics

Canonical guidance

• use generics for algorithms and data structures that genuinely repeat across types
• prefer plain interfaces or concrete types when they are simpler
• do not introduce type parameters purely for sophistication

Use when

• reusable containers
• helpers that operate the same way across element types
• removing real duplication without losing clarity

Avoid

• generic wrappers around single concrete use cases
• replacing ordinary interface-based design with needless type parameters
• unreadable constraints

Preferred pattern

func Index[S ~[]E, E comparable](s S, v E) int {
	for i := range s {
		if s[i] == v {
			return i
		}
	}
	return -1
}

Anti-pattern

• generic APIs whose only benefit is avoiding a handful of explicit overloads in application code

Explanation: This anti-pattern is tempting after learning generics, but abstraction without repeated use makes APIs harder to read without reducing real duplication.

Why

• generics are a tool for clarity and reuse, not a new default for all abstractions