Macros defined by C + +

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 Asctimedeclared in time. H.
__file__	The name of the current source file. __file__ expands to a string literal. To ensure the full path to the file is displayed, USE/FC (full path of Source Code file in diagnostics).
__func__	Returns the unqualified and unadorned name of the enclosing function as an array of char. void Foo () {printf ("%s\n", __func__);}//Prints "Foo"
__line__	The line number is in the current source file. The line number is a decimal integer literal. It can changed with a #line directive.
__stdc__	Indicates conformance with the Ansi/iso C99 standard. Defined as the integer literal constant 1 only if the/za compiler option was given and you were 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 formhh: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 M MM Date hh:mm:ss yyyy, where DDD is the abbreviated day of the week andDate is a integer from 1 to.

Microsoft-specific predefined Macros

Macro	Description
_atl_ver	Defines the ATL version, encoded as an integer literal.
__avx__	Defined when /arch:avx or /arch:avx2 is specified.
__avx2__	Defined when /arch:avx2 is specified.
_char_unsigned	The 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 is a integer literal encoded in the following format: mmmbbbbb p> Where, m is the major version of the runtime mm is the minor version of the runtime bbbbb is the build number.    //clr_ver.cpp//compile with:/clrusing namespace System;int main () {Console::WriteLine (__clr_v ER);}
__cplusplus_cli	Defined when you compile with/ CLR, /clr:pure, or /clr:safe. Value of __CPLUSPLUS_CLI is the integer literal 200406. __CPLUSPLUS_CLI is in effect throughout the translation unit. 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}
__cplusplus_winrt	Defined when do the /zw option to compile. The value of __CPLUSPLUS_WINRT is the integer literal 201009.
__counter__	Expands to an integer literal starting with 0 and incrementing by 1 every time it's used in a source file or included Hea DERs of the source file. __counter__ remembers it state is the precompiled headers. The following example uses __counter__ to assign unique identifiers to three different objects of the same type. First, assume the following class definition. The constructor takes an integer as a parameter. C++ Initialize object with a read-only unique idexampleclass::exampleclass (int nID) {M_nid = NID;} int Exampleclass::getid () {return m_nid;} In main, the application declares three objects of type ExampleClass, using __counter__ as the unique identif IER parameter. C++ Demonstration of __counter__, assigns unique identifiers to// different objects of the same type int main (int argc , char** argv) {//__COUNTER__ is initially defined as 0exampleClass E1 (__counter__);//have been referenced, __counter__ is now defined as 1exampleClass E2 (__COUNTER__);//__counter__ is now defined as 2exampleClass E3 (__counter__);p rintf ("E1 ID:%i\n ", E1. GetID ());p rintf ("E2 ID:%i\n", E2. GetID ());p rintf ("E3 ID:%i\n", E3. GetID ());//Output//------------------------------//E1 id:0//E2 id:1//E3 id:2 return 0;}
__cplusplus	Defined for C + + programs only.
_cpprtti	Defined for code compiled WITH/GR (Enable run-time Type information).
_cppunwind	Defined for code compiled by using one of the The/eh (Exception handling Model) flags.
_debug	Defined when you compile With/ldd,/MDd, AND/MTD.
_dll	Defined when/md OR/MDD (multithreaded DLL) is specified.
__funcdname__	Valid only in a function. Defines the decorated name of the enclosing function as a string literal. __funcdname__  is not expanded if your use the /ep or /p compiler option. The following example uses The __funcdname__, __funcsig__, and  __function__ macros to display FUNCTION information. c++  //demonstrates functionality of __function__, __funcdname__, and __funcsig__ macros void Examplefunction () {printf ("Function name:%s\n", __function__);p rintf ("Decorated Function name:%s\n", __funcdname__); printf ("Function Signature:%s\n", __funcsig__);//Sample output //------------------------------------------- ------ //function name:examplefunction //decorated function name: [email protected] @YAXXZ  // Function signature:void __cdecl examplefunction (void)}
__funcsig__	Valid only in a function. Defines the signature of the enclosing function as a string literal. __funcsig__ is not expanded if you use the/ep or/p compiler option. On a 64-bit operating system, the calling convention are __cdecl by default. See __funcdname__ for an example.
__function__	Valid only in a function. Defines the undecorated name of the enclosing function as a string literal. __function__ is not expanded if you use the/ep or/p compiler option. See __funcdname__ for an example.
_integral_max_bits	Reports the maximum size (in bits) for a integral type as an integer literal. Integral_max_bits.cpp#include <stdio.h>int Main () { printf ("%d\n", _integral_max_bits);}
_m_amd64	Defined for compilations that target x64 processors.
_m_arm	Defined for compilations this target ARM processors.
_m_cee	Defined for a compilation so uses any form of/ CLR (/clr:oldsyntax, /clr:safe, for example).
_m_cee_pure	Defined for a compilation that uses /clr:pure.
_m_cee_safe	Defined for a compilation that uses /clr:safe.
_m_ix86	Defined for compilations that target x86 processors. This isn't defined for x64 processors.
_m_arm_fp	Expands to a integer literal value indicating which /arch compiler option was used: In the range 30-39 if no /arch ARM option is specified, indicating the default architecture for ARM is used ( vfpv3). In the range 40-49 if /arch:vfpv4 is used. See/arch (x86) for more information.
_m_ix86_fp	Expands to an integer literal value indicating Which  /arch  compiler option was used: 0 if  /arch:ia32  was used. 1 if  /arch:sse  was used. 2 if  /arch:sse2 ,   /arch:avx  or  /arch:avx2  was used. This value was the default if  /arch  was not specified. when  /ARCH:AVX  is specified, the macro  __avx__  is Also Defined. when  /arch:avx2  is specified,  __avx__ and  __avx2__  are also defined. See /arch (x86)  for more information.
_m_x64	Defined for compilations that target x64 processors.
_managed	Defined to being 1 WHEN/CLR is specified.
_mfc_ver	Defines the MFC version, encoded as an integer literal.
_msc_build	Evaluates to a integer literal that contains the revision number component of the compiler ' s version number. The revision number is the fourth component of the period-delimited version number. For example, if the version number of the Visual C + + compiler is 15.00.20706.01, the _msc_build macro evaluates t o 1.
_msc_extensions	This macro was defined when you compile with the/ze compiler option (the default). Its value, when defined, is 1.
_msc_full_ver	Evaluates to a integer literal that encodes the major, minor, and build number components of the compiler's version Numbe R. The major number is the first component of the period-delimited version number, and the minor number is the second Componen T, and the build number is the third component. For example, if the version number of the Visual C + + compiler is 15.00.20706.01, the _msc_full_ver macro Evaluate S to 150020706. Type cl/? at the command line to view the compiler ' s version number.
_msc_ver	Evaluates to a integer literal that encodes the major and minor number of the compiler ' s version number. The major number is the first component of the period-delimited version number and the minor number are the second Componen T. For example, if the version number of the Visual C + + compiler is 17.00.51106.1, the _msc_ver macro evaluates to 1 The Type cl/? at the command line to view the compiler's version number.
__msvc_runtime_checks	Defined when one of the THE/RTC compiler options is specified.
_mt	Defined when/md OR/MDD (multithreaded DLL) OR/MT OR/MTD (multithreaded) is specified.
_native_wchar_t_defined	Defined when/zc:wchar_t is used.
_openmp	Defined when compiling with/openmp, returns an integer literal representing the date of the OpenMP specification Implemen Ted by Visual C + +. _openmp_dir.cpp//compile with:/OPENMP #include <stdio.h> int main () { printf ("%d\n", _OPENMP);}
_vc_nodefaultlib	Defined when /zl is used; See/zl (Omit Default Library Name) for more information.
_wchar_t_defined	Defined when/zc:wchar_t is used or if wchar_t are Defined in a system header file included in your project.
_win32	Defined for Applications for Win32 and Win64. Always defined.
_win64	Defined for Applications for Win64.
_wp64	Defined when Specifying/wp64.

Macros defined by C + +