C++ Standard

The cpp-library profile covers native C++ libraries, command line tools, and C ABI surfaces. It is also inherited by mixed-mode packages that combine Python, C++, and WASM.

Formatter

Owned C++ source uses a committed .clang-format at the repo root. The baseline follows the current Geometer and altium_monkey_cpp convention: LLVM base style, Allman braces, 4-space indentation, 100-column line limit, left pointer alignment, sorted includes, and preserved include blocks.

BasedOnStyle: LLVM
BreakBeforeBraces: Allman
IndentWidth: 4
ColumnLimit: 100
AllowShortFunctionsOnASingleLine: Empty
AllowShortIfStatementsOnASingleLine: Never
AllowShortLoopsOnASingleLine: false
AllowShortBlocksOnASingleLine: Empty
PointerAlignment: Left
SortIncludes: true
IncludeBlocks: Preserve
SpaceAfterCStyleCast: false
SpaceBeforeParens: ControlStatements

Static Analysis

New native projects commit .clang-tidy and run clang-tidy from a CMake-generated compile_commands.json. Existing projects may document temporary suppressions, but new warnings should not be added.

C and C++ projects enable google-runtime-int and treat it as an error for owned code. That gate blocks short, long, long long, unsigned long, and unsigned long long spellings in application-owned integer storage.

Integer Widths

Owned C++ code uses fixed-width standard integer types when width matters: std::int32_t, std::uint32_t, std::int64_t, and std::uint64_t. C ABI and C headers use the corresponding C spellings from <stdint.h> or <cstdint> without the std:: qualifier where the ABI requires C-compatible names.

Use std::size_t for object sizes and container indices, and std::ptrdiff_t for signed pointer or container differences. External-library integer spellings are allowed at the external API boundary, but owned code should convert them into the Wavenumber-owned type at the boundary.

Checks: >
  -*,
  google-runtime-int

WarningsAsErrors: >
  google-runtime-int

CMake

CMake and CTest are required. CMakePresets.json is required. Ninja is the default generator. Presets must set CMAKE_EXPORT_COMPILE_COMMANDS=ON so clang-tidy, editors, and agent tooling use the same compiler arguments as the build.

Warnings

Owned C++ code should compile with MSVC /W4 and Clang/GCC -Wall -Wextra -Wpedantic. Release-facing CI should treat warnings in owned code as errors. Third-party code is isolated from these warning policies unless explicitly patched and owned.

Native Tests

Register native tests with CTest and expose them through Rack strata. A typical native sequence is L0 compile/foundation, L1 algorithm tests, L2 CLI or public API integration, optional slow corpus/performance lanes, and L99 release signoff.

Complexity

C and C++ projects must run a Lizard-based complexity gate as part of the normal signoff loop. The gate scans owned native source, excludes generated and third-party code explicitly, and fails when project thresholds are exceeded. Canonical new-code limits are max_file_lines = 2200, max_function_lines = 220, and max_cyclomatic_complexity = 10.

Existing projects may carry a checked-in baseline for current debt. The baseline makes old debt visible, but new functions over the canonical cyclomatic complexity threshold must fail signoff.

[limits]
max_file_lines = 2200
max_function_lines = 220
max_cyclomatic_complexity = 10

[tools]
lizard = "fail"
clang_format = "report"
clang_tidy = "report"

Boundaries

Public headers live behind an intentional include boundary. Private headers stay under an internal or private source tree. C ABI boundaries must be versioned, must report errors without throwing C++ exceptions across the boundary, and must document ownership of allocated memory.