c++ - What does ## in a #define mean? - Stack Overflow
In other words, when the compiler starts building your code, no #define statements or anything like that is left. A good way to understand what the preprocessor does to your code is to get …
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 …
Difference between `constexpr` and `#define` - Stack Overflow
Feb 12, 2021 · So I read the interesting answers about what are the differences between constexpr and const but I was curious about are the differences between #define and …
How to declare variable and use it in the same Oracle SQL script?
I want to write reusable code and need to declare some variables at the beginning and reuse them in the script, such as: DEFINE stupidvar = 'stupidvarcontent'; SELECT stupiddata FROM …
MSBuild: set a specific preprocessor #define in the command line
Our solution was to use an environment variable with /D defines in it, combined with the Additional Options box in Visual Studio. In Visual Studio, add an environment variable macro, …
c preprocessor - Is there a good reason for always enclosing a …
#define _add_penguin(a) penguin ## a #define add_penguin(a) _add_penguin(a) #define WIDTH (100) #define HEIGHT 200 add_penguin(HEIGHT) // expands to penguin200 …
Why are #ifndef and #define used in C++ header files?
I have been seeing code like this usually in the start of header files: #ifndef HEADERFILE_H #define HEADERFILE_H And at the end of the file is #endif What is the purpose of this?
Array format for #define (C preprocessor) - Stack Overflow
Array format for #define (C preprocessor) Asked 13 years, 1 month ago Modified 4 years, 7 months ago Viewed 96k times
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 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 …