When to use
Use this skill when:
- adding new headers or refactoring includes
- encountering circular dependencies
- tightening the platform boundary
Source of truth
docs/REPO_LAYOUT.md— dependency direction and#ifdefpolicydocs/LIBC_POLICY.md— stdlib usage constraints
Include layering rules (must follow)
src/util/ → OS-header-free, no internal deps
↑
src/unicode/ → may include util; OS-header-free
↑
src/core/ → may include util, unicode, platform interface; OS-header-free
↑
src/platform/ → implements zr_platform.h; may include OS headers
Specific rules
src/util/**MUST be OS-header-freesrc/unicode/**may includesrc/util/**only; MUST be OS-header-freesrc/core/**may include util, unicode, andzr_platform.h; MUST be OS-header-freesrc/platform/**implementszr_platform.h; may include OS headers
Best practices
- Prefer forward declarations in headers to avoid deep include trees
- Keep ABI-visible headers POD-only (fixed-width ints)
- Ensure no OS headers are transitively included by core/unicode/util
- Platform
#ifdefexists only in platform backends and selection TU
Checklist
- No OS headers in core/unicode/util
- No circular includes
- Forward declarations where possible
- ABI headers use fixed-width types only