On Feb 7, 2008 1:05 PM, dplescia <[EMAIL PROTECTED]> wrote: > Please excuse this relatively naive question, but what is the > significance to the double-underline prefix of some types in C?
They are what are called 'reserved identifiers' which basically means that you, as a programmer, should not create any. You are free to use any that your implementation makes available however. The relevant section from C99: ----8< ---- 7.1.3 Reserved identifiers #1 Each header declares or defines all identifiers listed in its associated subclause, and optionally declares or defines identifiers listed in its associated future library directions subclause and identifiers which are always reserved either for any use or for use as file scope identifiers. -- All identifiers that begin with an underscore and either an uppercase letter or another underscore are always reserved for any use. [...] #2 No other identifiers are reserved. If the program declares or defines an identifier in a context in which it is reserved (other than as allowed by 7.1.4), or defines a reserved identifier as a macro name, the behavior is undefined. #3 If the program removes (with #undef) any macro definition of an identifier in the first group listed above, the behavior is undefined. ---->8---- -- PJH http://shabbleland.myminicity.com/ind
