Function parse_c_include_request 

pub fn parse_c_include_request(
    row: &[u8],
    directive_offset: usize,
) -> Result<Option<CIncludeRequest>, CPreprocessorError>

Parse an include request from one physical directive row.

row may contain phase-2 line splices; the returned offsets are mapped back to the original row byte space and then shifted by directive_offset.

Errors

Returns a diagnostic when the row is an include directive but its header payload is malformed.