The inline keyword specifies that a function is expanded inline at the point at which it is called rather than by using standard calling procedures. The compiler performs inline expansion of functions declared with the inline keyword.
You must invoke the optimizer with any --opt_level option to turn on definition-controlled inlining. Automatic inlining is also turned on when using --opt_level=3.
Example 1 shows usage of the inline keyword, where the function call is replaced by the code in the called function.