stepanov_skill

Overview

This skill encodes Alexander Stepanov's generic programming principles for designing C++ algorithms and types. It emphasizes putting algorithms first, expressing minimal requirements as concepts, and using iterators/ranges to separate algorithms from containers. The result is reusable, mathematically grounded code that composes cleanly across types.

How this skill works

I inspect algorithm designs and API surfaces and translate them into minimal template requirements, iterator categories, and regular-type contracts. I recommend iterator-pair and range overloads, document complexity and algebraic properties, and show how to implement iterators, algorithms, and compositions that follow Stepanov's patterns. I also suggest modern updates such as C++20 ranges and concepts.

When to use it

• Designing reusable algorithms intended to work across many container types
• Writing new container types that must interoperate with standard algorithms
• Refactoring code that currently couples algorithms to concrete containers
• Documenting template requirements and complexity guarantees
• Adopting C++20 ranges and concepts in existing codebases

Best practices

• Design algorithms first; derive the minimal concept requirements for template parameters
• Express requirements explicitly using concepts or clear documentation (iterator category, value semantics)
• Favor iterator-pair and range overloads, and prefer half-open ranges [first, last)
• Make user types regular: default-constructible, copyable, assignable, and comparable where appropriate
• Compose complex operations from simple, well-documented algorithms instead of monoliths

Example use cases

• Implementing a new sort or search algorithm that must work on any random-access iterator
• Creating a linked-list with a standards-compliant forward iterator and iterator_traits
• Refactoring container-specific utilities into iterator-based algorithms and range adapters
• Documenting template libraries with precise complexity and algebraic property statements
• Migrating legacy algorithms to C++20 ranges and adding concept-based constraints