# ISO Standard Predefined Macros

The ISO/ANSI standard for the C language requires that certain predefined macros be supplied with conforming compilers.

The compiler includes predefined macros in addition to those required by the standard. The default predefined macros differ among Windows*, Linux* operating systems. Differences also exist on Linux as a result of the -std compiler option.

The following table lists the macros that the Intel® oneAPI DPC++/C++ Compiler supplies in accordance with this standard:

Macro | Value
--- | ---
__DATE__ | The date of compilation as an 11-character string literal in the form `mm dd yyyy`. If the day is less than 10 characters, a space is added before the day value.
__FILE__ | A string literal representing the name of the file being compiled.
__LINE__ | The current line number as a decimal constant.
__STDC_HOSTED__ | Defined and value is 1 only when compiling a C translation unit with `/Qstd=c99`.
__STDC_VERSION__ | Defined and value is 199901L only when compiling a C translation unit with `/Qstd=c99`.
__TIME__ | The time of compilation as a string literal in the form `hh:mm:ss`.

Parent topic: Macros

## See Also

Additional Predefined Macros