C++ # is not followed by a macro parameter

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WebApr 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 … 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

Macros with Parameters (C++) - RAD Studio - Embarcadero

Web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 WebAug 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 … dv mark markacoustic ac101h

c++ - How to use #ifndef with macro argument? - Stack Overflow

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? 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. 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 … crystal brussel

Macros with Parameters (C++) - RAD Studio - Embarcadero

Macro Arguments (The C Preprocessor) - GNU Compiler …

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 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 crystal brush furWebDec 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 (; ). dvmb th

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

C++ # is not followed by a macro parameter

c++ - How to pass multi-argument templates to macros? - Stack …

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

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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 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...

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 … WebOct 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 …

Web2 days ago · I want to call the show.py in my Qt project. The p_stdout should be hello, but I just get an empty string "", the exit code is 1, and the exit status is QProcess::NormalExit. This is my

WebThe rules (which did not change in C++11): Reserved in any scope, including for use as implementation macros: identifiers beginning with an underscore followed immediately by an uppercase letter identifiers containing adjacent underscores (or "double underscore") Reserved in the global namespace: identifiers beginning with an underscore

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. dvmax northwesternWebMar 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 … dvm connection timed out翻译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 … crystal brushed nickel vanity lightsWebJan 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 … dvmd.campussoft.inWebJun 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__) crystal bryant first republic bankWebApr 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. crystal bryant powellWebNov 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 … dvm chat