c语言预定义标识符有哪些

白狐*狐玄墨

c语言预定义标识符有哪些

Jesse1

INTERNATIONAL STANDARD ©ISO/IEC ISO/IEC 9899:1999 (E)
在
160~161 Language §6.10.8
中

6.10.8 Predefined macro names
1 The following macro names148) shall be defined by the implementation:
_ _DATE_ _ The date of translation of the preprocessing translation unit: a character
string literal of the form "Mmm dd yyyy", where the names of the
months are the same as those generated by the asctime function, and the
first character of dd is a space character if the value is less than 10. If the
date of translation is not available, an implementation-defined valid date
shall be supplied.
_ _FILE_ _ The presumed name of the current source file (a character string literal).149)
_ _LINE_ _ The presumed line number (within the current source file) of the current
source line (an integer constant).149)
_ _STDC_ _ The integer constant 1, intended to indicate a conforming implementation.
_ _STDC_HOSTED_ _ The integer constant 1 if the implementation is a hosted
implementation or the integer constant 0 if it is not.
_ _STDC_VERSION_ _ The integer constant 199901L.150)
_ _TIME_ _ The time of translation of the preprocessing translation unit: a character
string literal of the form "hh:mm:ss" as in the time generated by the
asctime function. If the time of translation is not available, an
implementation-defined valid time shall be supplied.
2 The following macro names are conditionally defined by the implementation:
_ _STDC_IEC_559_ _ The integer constant 1, intended to indicate conformance to the
specifications in annex F (IEC 60559 floating-point arithmetic).
_ _STDC_IEC_559_COMPLEX_ _ The integer constant 1, intended to indicate
adherence to the specifications in informative annex G (IEC 60559
compatible complex arithmetic).
_ _STDC_ISO_10646_ _ An integer constant of the form yyyymmL (for example,
199712L), intended to indicate that values of type wchar_t are the
coded representations of the characters defined by ISO/IEC 10646, along
with all amendments and technical corrigenda as of the specified year and
month.
3 The values of the predefined macros (except for _ _FILE_ _ and _ _LINE_ _) remain
constant throughout the translation unit.
4 None of these macro names, nor the identifier defined, shall be the subject of a
#define or a #undef preprocessing directive. Any other predefined macro names
shall begin with a leading underscore followed by an uppercase letter or a second
underscore.
5 The implementation shall not predefine the macro _ _cplusplus, nor shall it define it
in any standard header.
Forward references: the asctime function (7.23.3.1), standard headers (7.1.2).【本帖转载自CSDN论坛，如有侵权请联系删除】