c/c++预定义宏

Predefined Macros

Visual Studio 2005

Other Versions

• Visual Studio 2010
• Visual Studio 2008
• Visual Studio .NET 2003

 

Names the predefined ANSI C and Microsoft C++ implementation macros.

The compiler recognizes predefined ANSI C macros and the Microsoft C++ implementation provides several more. These macros take no arguments and cannot be redefined. Some of the predefined macros listed below are defined with multiple values. See the following tables for more information.

ANSI-Compliant Predefined Macros

Macro	Description
__DATE__	The compilation date of the current source file. The date is a string literal of the form Mmm dd yyyy. The month name Mmm is the same as for dates generated by the library function asctime declared in TIME.H.
__FILE__	The name of the current source file. __FILE__ expands to a string surrounded by double quotation marks. To ensure that the full path to the file is displayed, use /FC (Full Path of Source Code File in Diagnostics). You can create your own wide string version of __FILE__ as follows: Copy #include <stdio.h> #define WIDEN2(x) L ## x #define WIDEN(x) WIDEN2(x) #define __WFILE__ WIDEN(__FILE__) wchar_t *pwsz = __WFILE__; int main() {}
__LINE__	The line number in the current source file. The line number is a decimal integer constant. It can be altered with a #line directive.
__STDC__	Indicates full conformance with the ANSI C standard. Defined as the integer constant 1 only if the /Za compiler option is given and you are not compiling C++ code; otherwise is undefined.
__TIME__	The most recent compilation time of the current source file. The time is a string literal of the form hh:mm:ss.
__TIMESTAMP__	The date and time of the last modification of the current source file, expressed as a string literal in the form Ddd Mmm Date hh:mm:ss yyyy, where Ddd is the abbreviated day of the week and Date is an integer from 1 to 31.

Microsoft-Specific Predefined Macros

Macro	Description
_ATL_VER	Defines the ATL version.
_CHAR_UNSIGNED	Default char type is unsigned. Defined when /J is specified.
__CLR_VER	Defines the version of the common language runtime used when the application was compiled. The value returned will be in the following format: Mmmbbbbb where, M is the major version of the runtime. mm is the minor version of the runtime. bbbbb is the build number. Copy // clr_ver.cpp // compile with: /clr using namespace System; int main() { Console::WriteLine(__CLR_VER); }
__cplusplus_cli	Defined when compiling with /clr, /clr:pure, or /clr:safe. Value of __cplusplus_cli is 200406. __cplusplus_cli is in effect throughout the translation unit. Copy // cplusplus_cli.cpp // compile with: /clr #include "stdio.h" int main() { #ifdef __cplusplus_cli printf("%d/n", __cplusplus_cli); #else printf("not defined/n"); #endif }
__COUNTER__	Expands to an integer starting with 0 and incrementing by 1 every time it is used in a compiland. __COUNTER__ remembers its state when using precompiled headers. If the last __COUNTER__ value was 4 after building a precompiled header (PCH), it will start with 5 on each PCH use. __COUNTER__ lets you generate unique variable names. You can use token pasting with a prefix to make a unique name. For example: Copy // pre_mac_counter.cpp #include <stdio.h> #define FUNC2(x,y) x##y #define FUNC1(x,y) FUNC2(x,y) #define FUNC(x) FUNC1(x,__COUNTER__) int FUNC(my_unique_prefix); int FUNC(my_unique_prefix); int main() { my_unique_prefix0 = 0; printf_s("/n%d",my_unique_prefix0); my_unique_prefix0++; printf_s("/n%d",my_unique_prefix0); }
__cplusplus	Defined for C++ programs only.
_CPPLIB_VER	Defined if you include any of the C++ Standard Library headers; reports which version of the Dinkumware header files are present.
_CPPRTTI	Defined for code compiled with /GR (Enable Run-Time Type Information).
_CPPUNWIND	Defined for code compiled with /GX (Enable Exception Handling).
_DEBUG	Defined when compiling with /LDd, /MDd, and /MTd.
_DLL	Defined when /MD or /MDd (Multithread DLL) is specified.
__FUNCDNAME__	Valid only within a function and returns the decorated name of the enclosing function (as a string). __FUNCDNAME__ is not expanded if you use the /EP or /P compiler option. </