A function interface specifies what a function does and the semantics callers can rely on. In the C library, clear interfaces help make everyday functionality usable portably and can separate compiler implementations from library implementations. section 8.0
Keep the contract distinct from implementation details:
- The interface states what the function does; interface comments explain its purpose. section 10.0
- Function code shows how the work is organized, while code comments describe implementation details. section 10.0
C headers typically hold interface specifications, while translation units hold implementations. Users can rely on the specification without needing to inspect how the function is implemented. section 10.0
Library functions
Functions such as printf, puts, and strtod provide everyday library functionality through defined interfaces and semantics. section 8.0
