E.8 Predefined Symbolic Constants

There are six predefined symbolic constants (Fig. E.1). The identifiers for each of these begin and (except for __cplusplus) end with two underscores. These identifiers and preprocessor operator defined (Section E.5) cannot be used in #define or #undef directives.

Fig. E.1 The predefined symbolic constants.

Symbolic constant Description
__LINE__ The line number of the current source-code line (an integer constant).
__FILE__ The presumed name of the source file (a string).
__DATE__ The date the source file is compiled (a string of the form "Mmm dd yyyy" such as "Aug 19 2002").
__STDC__ Indicates whether the program conforms to the ANSI/ISO C standard. Contains value 1 if there is full conformance ...

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