/* program define, undefine and redefine a macro*/#include<stdio.h>intmain(){/*Define MAXBUFF*/#defineMAXBUFF 100printf("\nMAXBUFF is :%d",MAXBUFF);#undefMAXBUFF/*Un-define MAXBUFF*/#defineMAXBUFF 200/*Redefine MAXBUFF*/printf("\nMAXBUFF is :%d",MAXBUFF);return0;} ...
intmain(){//代码1inta =10;intb = a +1;//a=10,b=11//代码2inta =10;intb = ++a;//a=11,b=11//代码2就是有副作用的return0; } 我们可以看到上述代码中代码1中的a值没有变,而代码2中的a值变了,我们就说代码2是有副作用的。 那如果宏里的副作用会影响到我们什么呢? #define MAX(X,Y...
Preprocessing without compilation can be useful as a debugging aid because it provides a way to see the result of include directives, conditional compilation directives, and complex macro expansions. The following table lists the options that direct the operation of the preprocessor. Option "-E" on...
__int128 undefine ? _CRT_SECURE_NO_DEPRECATE has no effect _CRT_SECURE_NO_WARNINGS Seems To Be Inconsistent. _HAS_EXCEPTIONS _tcscpy _USE_32BIT_TIME_T -Embedding in COM server process Command Line .ini file write/read .lib is not a valid Win32 application - Visual Studio 2017 .rsrc ...
C preprocessor macros do have a well-defined scope, but that scope is only relevant to the preprocessing phase, not any other phase of translation.That scope is "From point of definition until the end of the current translation unit, or until the macro is undefined using#undefineor redefined...
To undefine a macro means to cancel its definition. This is done with the `#undef' command. `#undef' is followed by the macro name to be undefined.Like definition, undefinition occurs at a specific point in the source file, and it applies starting from that point. The name ceases to ...
Like a C preprocessor Include #include"file.js" Include and parse a file. Define //Define a constant #defineMY_CONST42 //Define a macro #defineSUM(a,b)a + b Create a constant or a macro. Undefine #undefMY_CONST Delete a constant or a macro. ...
Yield macro from Windows.h conflicting with concurrency::Context::Yield The Concurrency Runtime previously used #undef to undefine the Yield macro to avoid conflicts between the Yield macro defined in Windows.h h and the concurrency::Context::Yield function. This #undef has been removed and a ...
Description File Enables the support for multi-threaded applications Displays the elapsed time as part of the output information on each part of the compilation process Undefines macro VisualDSP++ 4.5 C/C++ Compiler and Library Manual for Blackfin Processors 1-19 Compiler Command-Line Interface Table...
Removes (undefines) a name previously created with #define.Syntax复制 #undef identifier RemarksThe #undef directive removes the current definition of identifier. Consequently, subsequent occurrences of identifier are ignored by the preprocessor. To remove a macro definition using #undef, give only ...