Is it possible to use a if statement inside #define?
As far as I know, what you're trying to do (use if statement and then return a value from a macro) isn't possible in ISO C... but it is somewhat possible with statement expressions (GNU …
c++ - 'static const' vs. '#define' - Stack Overflow
Oct 28, 2009 · #define is a compiler pre processor directive and should be used as such, for conditional compilation etc.. E.g. where low level code needs to define some possible …
What is the purpose of the #define directive in C++?
Nov 27, 2015 · In the normal C or C++ build process the first thing that happens is that the PreProcessor runs, the preprocessor looks though the source files for preprocessor directives …
c - #Define VS Variable - Stack Overflow
Jun 18, 2012 · The scope of #define is limited to the file in which it is defined. So, #defines which are created in one source file are NOT available in a different source file. In short, #defines …
What's the difference in practice between inline and #define?
Aug 24, 2010 · Macros (created with #define) are always replaced as written, and can have double-evaluation problems. inline on the other hand, is purely advisory - the compiler is free …
What is the difference between #define and const? [duplicate]
DEFINE is a preprocessor instruction (for example, #define x 5). The compiler takes this value and inserts it wherever you are calling x in the program and generate the object file. "Define" …
c# - Define #define, including some examples - Stack Overflow
#define is a special "before compile" directive in C# (it derives from the old C preprocessor directives) that defines a preprocessor symbol. Coupled with #if , depending on what symbols …
c++ - Why use #define instead of a variable - Stack Overflow
May 14, 2011 · Most compilers will allow you to define a macro from the command line (e.g. g++ -DDEBUG something.cpp), but you can also just put a define in your code like so: #define …
Why are #ifndef and #define used in C++ header files?
#define will declare HEADERFILE_H once #ifndef generates true. #endif is to know the scope of #ifndef i.e end of #ifndef. If it is not declared, which means #ifndef generates true, then only …
How do I define a function with optional arguments?
These two aren't equivalent: * In the first example, 'b' is still a positional argument that must be provided: * in the second example, 'b' is a true optional argument that can be ommitted (and in …