C++ # is not followed by a macro parameter

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WebJan 4, 2016 · Such macros are called by writing. macro_identifier () in the subsequent source code. The syntax is identical to that of a … 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 …

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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)) {} 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 … simpsons wedding quotes

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WebJun 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 … WebApr 13, 2024 · Then, we initialize each thread giving it the function to execute ** multiply_threading ** that has the following signature: ```c void multiply_threading(Matrix& result, const int thread_number, const Matrix& m1, const Matrix& m2); ``` The first parameter is the output matrix, The second parameter is the thread number (later on … simpson sweatpants

c - # not followed by macro parameter - Stack Overflow

Optional Parameters with C++ Macros - Stack Overflow

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 (; ). WebNov 19, 2024 · There are 2 problems with your macro definition: It uses incorrect syntax The name of a variable may be passed as a; in this case you cannot simply put the variable next to 2 string literals to do a concatenation. The latter problem can be solved by using a string and the + operator or simply using multiple printf s. simpsons weed episodeWebJun 9, 2024 · You can define a variadic macro in C++ like: #define FOO (x, ...) bar (x, __VA_ARGS__) But calling FOO as FOO (1) results in the macro expansion bar (1,) which is obviously a syntactical error and won't compile. Therefore GCC includes a GNU extension: #define FOO (x, ...) bar (x, ##__VA_ARGS__) razor pages search

"WebSep 25, 2015 · It's a pity that the defined operator is available only in the context of #if and #ifelse, but not for macro expansions. As it stands, I agree with rici about the solutions … " - C++ # is not followed by a macro parameter

C++ # is not followed by a macro parameter

Optional Parameters with C++ Macros - Stack Overflow

WebJun 20, 2015 · You could get a clear compilation error if you converted the selected argument which is supposed to be a MACRO name to string using # (the pound sign) and compared it's first n characters with the expected prefix and if there is no match, printed an informative error. – AturSams Jan 7, 2014 at 16:01 1 WebMar 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 …

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WebSep 26, 2024 · 1. I'm trying to write a macro that generates code for an object pool for any given class of objects in C. I keep getting error: '#' is not followed by a macro … WebNov 8, 2024 · You cannot use preprocessor conditional directives inside a macro. Generally speaking, the solution is to turn that inside out: use conditional directives to define the …

WebJan 17, 2024 · check whether the identifier is or is not currently defined as a macro name. Their conditions are equivalent to #if defined identifier and #if !defined identifier respectively. Then again if you are not sure what is the macro name and what are the parameters etc.. From standard §6.10.3.p10 A preprocessing directive of the form WebIt seems like the simplest solution is to define an additional macro that is missing the default parameter. #define MACRO1 ( PARAM1 , PARAM2 ) & ( PARAM1 + PARAM2 ) // or …

WebMay 30, 2012 · do not enclose arguments of macro in parentheses in the macro body, so if those arguments are expressions, operators with different precedences in those … WebJun 4, 2016 · A better way to avoid the warning is to use a dummy macro that expands to nothing, e.g. #define NOARG then you can use MY_MACRO (NOARG, bar, baz). – Rufflewind Jun 4, 2016 at 12:43 Add a comment Your Answer By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy Not the …

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.

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 … razor pages shopping cartWebNov 6, 2024 · # # Compile as C++11, supported in ROS Kinetic and newer # add_compile_options(-std=c++11) # # Find catkin macros and libraries # # if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz) ... # # To declare and build dynamic reconfigure parameters within this # # package, follow these … simpsons wedding dressWebDec 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, … simpsons we know all your secretsWebJan 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 … simpsons weddingWebAug 2, 2024 · Each formal parameter in token-string that is not preceded by a stringizing ( # ), charizing ( #@ ), or token-pasting ( ##) operator, or not followed by a ## operator, is … razor pages specify layoutWebApr 4, 2024 · (since C++11) Otherwise, the behavior is undefined. # and ## operators In function-like macros, a # operator before an identifier in the replacement-list runs the … simpsons website officialWebSep 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. simpsons website