C++ # is not followed by a macro parameter

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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 … 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...

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WebApr 10, 2024 · I want to use macros or template metaprogramming to generate some code for me. So basically these enum values are 1 shifted by the index of enum I want to avoid any typos in case in future some adds a new enum value and I can simply define an array of string for the named enums and generate functions for it and return value based on the … 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. sharing success cobank

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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 # … WebJun 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__) 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 sharing success quotes

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WebJan 4, 2016 · Macros with Parameters (C++) navigation search Go Up to The Preprocessor Index The following syntax is used to define a macro with parameters: #define macro_identifier () Contents 1 Nesting Parentheses And Commas 2 Side Effects and Other Dangers 3 Converting Actual Arguments to … 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 … pops barber shop pine bluff arWebAug 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)) {} pops barber shop port charlotte fl

"WebNov 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 … " - C++ # is not followed by a macro parameter

C++ # is not followed by a macro parameter

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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 … WebDec 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, …

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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 …

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. 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 …

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? 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 …

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

WebSometimes (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. sharing student data with parentsWebMar 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. sharing student data with familiesWebApr 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 … sharing success criteria with studentsWeb我正在尝试编写一个带有工作线程的UDP服务器，该工作线程一直在调用GetQueuedCompletionStatus 。我已经可以使用WSARecvFrom成功接收数据，但使用WSASendTo发送数据会导致以下错误： : The attempted operation is not suppor pops barn sheephurst lane mardenWebSep 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 … sharing successWebMay 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 … sharing supportWebSep 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 … pops barn sheephurst lane