What is the purpose of the #define directive in C++?
May 10, 2010 · 0 in C or C++ #define allows you to create preprocessor Macros. In the normal C or C++ build process the first thing that happens is that the PreProcessor runs, the …
c - #Define VS Variable - Stack Overflow
Jun 18, 2012 · #define WIDTH 10 is a preprocessor directive that allows you to specify a name (WIDTH) and its replacement text (10). The preprocessor parses the source file and each …
Why do most C developers use define instead of const?
Mar 4, 2017 · #define simply substitutes a name with its value. Furthermore, a #define 'd constant may be used in the preprocessor: you can use it with #ifdef to do conditional compilation …
What is the difference between #define and const? [duplicate]
The #define directive is a preprocessor directive; the preprocessor replaces those macros by their body before the compiler even sees it. Think of it as an automatic search and replace of your …
c++ - Declaring a function using #define - Stack Overflow
Jul 9, 2018 · The #define version is still a macro. The code is expanded at the invocation site. It has all the expected problems (with macros) including namespace pollution and unexpected …
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 …
What is the scope of a #define? - Stack Overflow
Jul 6, 2016 · What is the scope of a #define? I have a question regarding the scope of a #define for C/C++ and am trying to bet understand the preprocessor. Let's say I have a project …
c++ - 'static const' vs. '#define' - Stack Overflow
Oct 28, 2009 · Is it better to use static const variables than #define preprocessor? Or does it maybe depend on the context? What are advantages/disadvantages for each method?
c - #ifdef inside #define - Stack Overflow
I am trying to write something like this: #define COV_ON(x) \ #ifdef COVERAGE_TOOL \ _Pragma (COVERAGE #x) #endif Is there any way to define COV_ON like this? I know what I …
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 …