There are multiple problems with your macro: it expands to a statement, so you cannot use it as an expression the arguments are not properly parenthesized in the expansion: invoking this macro with anything but variable names or constants will produce problems. the arguments are evaluated multiple times: if you invoke the macro with arguments that have side effects, such …

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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.

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. #define XSTR(x) STR(x) #define STR(x) #x The value of a macro can then be displayed with: #pragma message "The value of ABC: " XSTR(ABC) See: 3.4 Stringification in the gcc online ...

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 preprocessor looks though the source files for preprocessor directives like #define or #include and then performs simple operations with them.

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?

Jan 24, 2024 · How do I define a preprocessor variable through CMake? The equivalent code would be #define foo.

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 parameter behaviour.

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