The preprocessor function __option() returns the state of pragma settings at compile-time. The syntax is
__option( setting-name )
where setting-name is the name of a pragma that accepts the on , off , and reset arguments.
If setting-name is on , __option(setting-name) returns 1. If setting-name is off , __option(setting-name) returns 0. If setting-name is not the name of a pragma, __option(setting-name) returns false. If setting-name is the name of a pragma that does not accept the on , off , and reset arguments, the compiler issues a warning message.
Using the __option() preprocessor function shows an example.
#if __option(ANSI_strict) #include "portable.h" /* Use the portable declarations. */ #else #include "custom.h" /* Use the specialized declarations. */ #endif