C++ # is not followed by a macro parameter

WebApr 10, 2024 · Macros are expanded by the preprocessor during preprocessing. c. #ifdef, #ifndef, #if, #else, #elif, and #endif: These directives are used for conditional compilation. They allow the preprocessor to include or exclude sections of code based on whether a certain macro is defined or not, or based on the value of an expression. Include Guards WebMar 2, 2016 · Since you added the C++ tag not using macros is a valid answer. If you just want to talk about the pre-processor just tag it as pre-processor and not C++ – Martin York Nov 22, 2010 at 23:20 15 @Martin: The preprocessor is as much a part of C++ as the STL is; should questions about the STL be tagged [stl] and not [c++] too?

c++ - How can I retrieve the last argument of a C99 variadic macro …

WebAug 17, 2011 · This question describes a way to suppress the unused parameter warning by writing a macro inside the function code: Universally compiler independent way of implementing an UNUSED macro in C/C++ But I'm interested in a macro that can be used in the function signature: void callback (int UNUSED (some_useless_stuff)) {} WebJun 3, 2014 · The C preprocessor throws an error because the STATIC_ASSERT macro only takes one parameter. The two main solutions to this problem are to use double parentheses and, more recently, to use variadic macros: // Invoke the macro this way... hill wallpaper https://joellieberman.com

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WebMar 1, 2012 · You can use a variadic macro and then pass the string format and the function parameters to it. The macro won't be exactly the same for every function (as … WebJan 25, 2024 · No, this is not possible. During translation, all preprocessing directives ( #define, #include, etc.) are executed before any macro expansion occurs, so if a macro expands into a preprocessing directive, it won't be interpreted as such - it will be interpreted as (invalid) source code. Share Improve this answer Follow answered Jan 24, 2024 at … WebJan 17, 2024 · From standard - §6.10.1p5. Preprocessing directives of the forms. # ifdef identifier new-line groupopt # ifndef identifier new-line groupopt. check whether the … hill walks near glasgow

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C++ # is not followed by a macro parameter

c++ - How to resolve "must specify at least one argument for ...

WebNov 20, 2024 · You can fix this with an extra "helper" macro: #define MAX_NAME_LEN 15 #define STRINGIFY (s) \ #s #define PRINT_CELL (x) \ printf (" %" STRINGIFY … WebSep 9, 2012 · A common way to enforce macros end on a semicolon, and creating the same effect (i.e., creating a new local block), would be to use #define CHECK_TYPE (type,var) do { ... } while (0), which is probably preferable in almost all cases. – Ionic Mar 19, 2024 at 3:44 Add a comment 3 No, macros can't provide you any typechecking.

C++ # is not followed by a macro parameter

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WebNov 6, 2008 · C and C++ languages explicitly prohibit forming preprocessor directives as the result of macro expansion. This means that you can't include a preprocessor directive … WebNov 6, 2008 · C and C++ languages explicitly prohibit forming preprocessor directives as the result of macro expansion. This means that you can't include a preprocessor directive into a macro replacement list.

Webpasses two arguments to macro: array[x = yand x + 1]. If you want to supply array[x = y, x + 1]as an argument, you can write it as array[(x = y, x + 1)], which is equivalent C code. All … WebOct 28, 2024 · Argument substitution expansion only occurs if the parameter in the macro corresponds to one in the replacement list (and that parameter isn't stringified with the # …

WebMar 1, 2012 · The C macro system cannot implicitly reference the parameters. You'd have to pass them to it. As a small win macros can count their arguments, so it would be TRACE (foo,bar) instead of TRACE2, TRACE3 etc. That's not significantly worse than writing TRACE () at the start of the function. Actually printing the values would be fine. WebMar 31, 2015 · 1 #ifndef DEF_H 2 #define DEF_H 3 #define DEBUG_MODE 4 #define DEBUG_INFO (message) \ 5 #ifdef DEBUG_MODE \ 6 cout << message << endl; \ 7 …

WebJun 25, 2016 · To use proper C99 variadic macros, you should be compiling with a C compiler that supports C99 (like gcc), not a C++ compiler, since C++ doesn't have standard variadic macros. – Chris Lutz Mar 25, 2009 at 2:13 Well, I assumed C++ is a super set of C in this regard .. – hasen Mar 25, 2009 at 3:46

WebDec 12, 2024 · A macro is a piece of code in a program that is replaced by the value of the macro. Macro is defined by #define directive. Whenever a macro name is encountered by the compiler, it replaces the name with the definition of the macro. Macro definitions need not be terminated by a semi-colon (; ). smart business pittsburghWebMar 25, 2006 · C++ and C). By definition a macro (the part after the #define) ends on the same line. This can be partially ameliorated by the use of continuation lines (where the … hill ward 2WebApr 8, 2024 · C++ is a versatile and powerful programming language that offers a wide range of built-in functions to help developers manipulate strings. One such function is find (), which is used to search for a specific substring within a larger string. In this blog post, we'll take a deep dive into find () and explore its syntax, usage, and examples. smart business objectives definitionWebJun 22, 2011 · As JAB pointed, macros are different than functions, they do not require the type of arguments #define TRACERPTR (pReporter, eComponent, eLevel, sFormat, formatArgs...) \ if (pReporter != NULL) { pReporter->trace (eComponent, eLevel, sFormat, ##formatArgs); } Share Improve this answer Follow answered Jun 20, 2011 at 19:27 … hill ward henderson paWebOct 29, 2024 · The #if(!(x)) needs to be a regular if, not a preprocessor if. And you need to make sure you have a backslash at the end of every line you want in the macro (except … smart business phone mp54WebDec 12, 2013 · This won't work if I pass it a template that has more than one parameter, because the comma in the is interpreted as separating the macro arguments, … hill wallack lawWebSometimes (like the Visual C++), the debugging info is extracted into a separate file - but you would need that file and know its format, to extract that info. And you would be getting only the debug info. Not the compiled code. The parameters are the way to go. smart business pack v.4