(cpp.info.gz) Macros

 
 3 Macros
 ********
 
 A "macro" is a fragment of code which has been given a name.  Whenever
 the name is used, it is replaced by the contents of the macro.  There
 are two kinds of macros.  They differ mostly in what they look like
 when they are used.  "Object-like" macros resemble data objects when
 used, "function-like" macros resemble function calls.
 
    You may define any valid identifier as a macro, even if it is a C
 keyword.  The preprocessor does not know anything about keywords.  This
 can be useful if you wish to hide a keyword such as `const' from an
 older compiler that does not understand it.  However, the preprocessor
 operator `defined' ( Defined) can never be defined as a macro,
 and C++'s named operators ( C++ Named Operators) cannot be
 macros when you are compiling C++.
(cpp.info.gz) Macros

Menu
