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 …

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.

Just do something like this: #ifdef USE_CONST #define MYCONST const #else #define MYCONST #endif Then you can write code like this: MYCONST int x = 1; MYCONST char* …

The \ at the end of each line is to signal line continuation (i.e. to tell the compiler "this macro continues on the next line") The ( { is a statement expression (GNU extension; not part of …

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 …

The space before the = is interpreted as part of the name, and the space after it (as well as the quotation marks) are interpreted as part of the value. So the variable you’ve created can be …

Nov 27, 2015 · 2 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 …

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 …

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?

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?