---

name: following-conventions description: C++ coding conventions. Use when editing .cpp/.hpp files or asking about C++ style.

C++ Coding Conventions

Tooling

Use clang-format for formatting and clang-tidy for linting. The .clang-format and .clang-tidy files in the repository root are authoritative—run the tools and trust the output.

Style Conventions

These are not enforced by tooling:

• West const: const T& not T const&
• Prefer auto: Use almost-always-auto, make conversions explicit (e.g., auto x = int64_t{0})
• Vertical whitespace: Avoid blank lines within functions. Use comments to separate logical blocks instead.
• Naming: See naming.md

File Organization

• Headers: .hpp, implementation: .cpp
• Forward declarations: <module>/fwd.hpp
• Use #pragma once—no manual include guards

Classes

Member order:

1. public, then protected, then private
2. Within each: constructors, operators, mutating members, accessors

Rules:

• Mark single-argument constructors explicit
• Use explicit(false) when implicit conversion is intentional
• Follow the rule of zero or rule of five
• Declare move operations noexcept
• Use struct for simple data aggregates where the public members are the API

Template Metaprogramming

• Use class for template parameters; typename only for dependent types
• Name parameters T, packs Ts, arguments x, packs xs
• Provide *_t and *_v helpers for traits

Comments

• FIXME: for bugs, TODO: for improvements (colon required)
• Doxygen: /// with Markdown—do not use @param, @returns, @pre, @post