Asimple macrois a kind of abbreviation. It is a name which stands for a fragment of code. Some people refer to these asmanifest constants. Before you can use a macro, you mustdefineit explicitly with the`#define'command.`#define'is followed by the name of the macro and then the code ...
#undef defined_macro_nameConsider the exampleHere, we are defining a macro MAXBUF, then un defining and redefining macro with new value./* program define, undefine and redefine a macro*/ #include <stdio.h> int main() { /*Define MAXBUFF*/ #define MAXBUFF 100 printf("\nMAXBUFF is : ...
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...
Secondly, you need to undefine the macro __STRICT_ANSI__, if you not, the functions fdopen, fileno and strptime will not available.the sample command like this:$ export CFLAGS="-U__STRICT_ANSI__ -I$libev_PREFIX/include -L$libev_PREFIX/lib" $ export CXXFLAGS=$CFLAGS $ ./configure $...
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. ...
__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 ...
Undefine preprocessor symbolsym. -Idir Add directorydirto the search path for included files. Note that there is no default search path. When an include file is not found the include directive is simply ignored with a warning (but see also option-Zpass). Therefore all include directives are ...
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 ...
(-U [macro]) Undefine All Preprocessor Definitions Undefines all previously defined preprocessor values. (-undef) Show Includes Generates a list of include files with compiler output. (-H) Code Generation Expand table PropertyDescriptionChoices Position Independent Code Generates position-independent ...