IDL 4.2 · §7.3

Preprocessor

A full C-style preprocessor runs ahead of parsing: #include (with search paths), #define / function-like macros, conditional compilation (#if / #ifdef / #else) and #pragma. Include cycles and macro recursion are detected.

Example

#include "common.idl"
#define MAX 1024
#ifndef EMBEDDED
struct Big { octet data[MAX]; };
#endif

ZeroDDS support

OMG IDL 4.2 section§7.3
Implementationidl/src/preprocessor
Testspreprocessor.rs
Status✓ RC3 — parsed, validated and code-generated across all target languages.

See also: IDL construct coverage · idl-4.2 audit · OMG IDL 4.2 spec