/sys$common/syshlp/helplib.hlb CC, Language topics, Storage Class Modifiers, __forceinline  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Similar to the __inline storage-class modifier, the __forceinline
  storage-class modifier marks a function for inline expansion.
  However, using __forceinline on a function definition and prototype
  tells the compiler that it must substitute the code within the
  function definition for every call to that function.  (With
  __inline, such substitution occurs at the discretion of the
  compiler.)

  Syntax:

       __forceinline [type] function_definition