F.8. Predefined Symbolic Constants

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

Figure F.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 and is undefined otherwise.

__TIME__

The time the source file is compiled (a string literal of the form "hh:mm:ss").

__cplusplus

Contains the value 199711L (the date the ISO C++ standard was approved) if the file is being compiled by a C++ compiler, undefined otherwise. Allows a file to be set up to be compiled as either C or C++.






C++ How to Program
C++ How to Program (5th Edition)
ISBN: 0131857576
EAN: 2147483647
Year: 2004
Pages: 627
Simiral book on Amazon

Flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net