May 14, 2011 · What is the point of #define in C++? I've only seen examples where it's used in place of a "magic number" but I don't see the point in just giving that value to a variable instead.

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 …

How can I use #if inside #define in the C preprocessor? Asked 15 years, 7 months ago Modified 8 months ago Viewed 51k times

Oct 30, 2013 · 8 #define is used to define compile-time constants that you can use with #if to include or exclude bits of code.

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 …

#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 …

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?

Jun 21, 2019 · return otherModule.operation(); }; }); Maybe you got mixed up with the JSONP service dependency format, which uses require () to load the service, and then specify define …

Aug 4, 2021 · I am writing a docker-compose.yaml file for my project. I have checked the volumes documentation here . I also understand the concept of volume in docker that I can mount a …

I know that this is a long time after the original query, but this may still be useful. This can be done in GCC using the stringify operator "#", but it requires two additional stages to be defined first. …