C macro pound sign. The C standard states in 6.

• C macro pound sign Sometimes you may want to convert a macro argument into a string constant. Jan 10, 2015 · In other words, the C preprocessor is a preprocessor for C (and C++) and not a completely general purpose tool. It also isn't type generic, because when you invoke the macro, the type must be known. A C macro is just a preprocessor command that is defined using the #define preprocessor directive . 10. However, it does not seem to make any sense in terms of the above line. To know more, refer to this article – Macros and its types in C Aug 28, 2007 · Hi, I never truly understand how a macro with ## work in C, for example, if I define #define X X##_YZ[2] what and how does this translated into after compilation? Can't find similar info. BOOST_SERIALIZATION_SPLIT_FREE(my_class) is the macro, which is short for the following free serialize function template: namespace boost { namespace serialization { template<class Archive> inline void serialize( Archive & ar, my_class & t, const unsigned int file_version ){ split_free(ar, t, file_version); } }} The # (pound sign) is a preprocessor directive when it occurs as the first non-whitespace character on a line. They are known as stringizing and token pasting operators and are used in macro definition with #define preprocessor. Therefore, you cannot create a comment by concatenating ‘ / ’ and ‘ * ’. Arguments passed in the macros can be used in the expression. VBA function: kn = 1#: pn = 1#: y = 1# I know the pound sign is used to declare a variable as a double in Excel VBA. Both are well accepted and the final drafts available by a short search. The syntax is simple--simply prefix the token with a pound sign (#). During the preprocessing stage, the C preprocessor (a part of the C compiler) simply substitutes the body of the macro wherever its name appears. Jan 16, 2013 · In this context (applied to a parameter reference in a macro definition), the pound sign means to expand this parameter to the literal text of the argument that was passed to the macro. It permits separate tokens to be joined into a single token, and therefore, can't be the first or last token in the macro definition. tom Feb 9, 2015 · I am trying to understand a vba function with the pound and colon symbol interspersed throughout it. This is called stringizing. The symbols are written as follows: Function-like macros with (). Sep 6, 2024 · C macros are powerful tools that allow developers to extend the language's capabilities and write more efficient, maintainable code. "n". Dec 26, 2013 · In short words, it's a macro. Write a small static function for swapping; that's clearer in my opinion. The symbols are written as follows: Function-like macro names with (). Logic tells me the backslash means the declaration continues onto the next line. What does the above function do? Jun 15, 2012 · Hi All, I'd like to enter a pound sign (£) as text in a cell by a VBA statement. #define PRINT_TOKEN(token) printf(#token " is %d", token) For instance, PRINT_TOKEN(foo) would expand to All preprocessor commands begins with the hash (pound) symbol #. We would like to show you a description here but the site won’t allow us. h" for C or #include "cname" for C++. FormulaR1C1 = "L" Thanks, Keep in mind that the C preprocessor converts comments to whitespace before macros are even considered. 7 (C++ has much the same text): A preprocessing directive of the form # new-line has no effect. See full list on learn. – I understand the first line defines a macro, however I am not well versed in preprocessor shenanigans in C++ and so I'm lost over there. In this comprehensive guide, we'll dive deep into advanced preprocessor usage, exploring complex macro techniques that can significantly enhance your C programming skills. Jun 20, 2015 · Given that the macro doesn't work for compound expressions, you don't buy much with it. C is standardised as ISO 9899::2011, C++ also has an ISO standard. #define MACRO_NAME(ARG1, ARG2,. what ++" parts. The usage of # (pound sign) and ## (double pound sign) in C language macro definition 1; The pound sign ("#") appears in the url; Read a file, display all lines except those beginning with the pound sign (#) Talk about C language macro definition again; C# single sign-on; Single sign-on based on C#; Think about single sign-on (SSO) Jul 14, 2023 · #define MACRO_NAME (expression within brackets) For Defining Expression with Parameters. In this article, we will learn about these operators and how to use them in C programs. The C standard states in 6. Parameters are not replaced inside string constants, but you can use the ‘ # ’ preprocessing operator instead. The C FAQ has a question and strong opinions about type-generic swap macros, too. Go to System Preferences > Keyboard > Text, and set a replacement like “(pound)” for the £ sign. When a macro parameter is used with a leading ‘ # ’, the preprocessor replaces it with the literal text of the actual argument, converted to a string Why does the author use the double pound in the function definition part of the macro and not when its being used as the class variable being incremented? EDIT: I get that the double pound is for concatenation, but my confusion comes from why the double pound is not necessary in the "CountSeen. A C macro is just a preprocessor command that is defined using the #define preprocessor directive. Another potentially useful macro option is to turn a token into a string containing the literal text of the token. Connector ## (two pound signs) Don't know what character # (a pound sign) ## The connection symbol consists of two pound signs. But it cannot be the first or last substring. googling, would appreciate some detailed information. I tried to record a macro inserting a pound sign via Insert/Symbol but it produced ActiveCell. . microsoft. Always check an authoritative source instead of relying on other resources. This is my macro for the alt code for £ :) {KC_RALT,KC_P0,KC_P1,KC_P6,KC_P3} The single pound sign is to perform string operations on the following macro parameters, which means to enclose the following parameters in double quotes. Any suggestions? The macro was simply the symbol. Also, # and ## perform operator replacement and merging during the preprocessor scanning phase. Aug 5, 2024 · Note: if an argument of a function-like macro includes commas that are not protected by matched pairs of left and right parentheses (most commonly found in template argument lists, as in assert (std:: is_same_v < int, int >); or BOOST_FOREACH (std:: pair < int, int > p, m)), the comma is interpreted as macro argument separator, causing a compilation failure due to argument count mismatch. Unlike normal parameter replacement, the argument is not macro-expanded first. Dec 25, 2024 · Pound sign on Windows. You can use third-party software like AutoHotkey to create a custom shortcut. Feb 18, 2015 · @Anonymouse: Except in American English, where # is a pound sign (sometimes used to represent a pound weight), hash is banned in most states, and £ is a symbol of colonial oppression. what ++" and "CountTaken. For example, have the macro replacement: #define label(x) !@!x Jun 30, 2021 · This page tries to list all the macro symbols that are available from the Standard Library. Jan 2, 2025 · In C, # and ## operators are preprocessor operators using in macros for token manipulation. com Aug 2, 2021 · The double-number-sign or token-pasting operator (##), which is sometimes called the merging or combining operator, is used in both object-like and function-like macros. Two lines are required to allow extra expantion of macro parameter, for example: Two lines are required to allow extra expantion of macro parameter, for example: If you were willing to type out X (where X is the max number of args you want to support) versions of a macro you could get a close approximation of an IS_EMPTY() macro using a doctored NUM_ARGS MACRO (that starts counting at 0 instead of 1) and the same concatenation technique used above. It is harder to make it work in a scenario where you have #include USR_HEADER(name) in the code, and you want it to become #include "name. Thanks in advance. Operator # In C preprocessor, a character sequence enclosed by quotes is considered a token and its content is not analyzed. This might be useful for printing out the token. ) (expression within brackets) There are a few more ways using which we can define macros. ; Type-generic macro names marked with (generic). All preprocessor commands begins with the hash (pound) symbol #. How can I ensure the £ symbol displays correctly in emails or documents? Ensure that the font used supports the currency Jan 26, 2018 · This is stringize operation, it will produce a string literal from macro parameter, e. For example, the example in the article: #define PRINT (NAME) printf ("token"#NAME"=%d\n", token##NAME) When a macro parameter is used with a leading ‘#’, the preprocessor replaces it with the literal text of the actual argument, converted to a string constant. g. If you want to be unambiguous, it's an "octothorpe". Mar 6, 2025 · This page tries to list all the macro symbols that are available from the standard library. The double pound sign is used for connection. Or just #, since we're typing not speaking. You can put as much whitespace between ‘ ## ’ and its operands as you like, including comments, and you can put comments in arguments that will be concatenated. Jul 16, 2009 · This works for the question, where the name to be included doesn't need . Its function is to connect two substrings (tokens) in the macro definition with parameters to form a new substring. h appended. FThreadSafeStaticStat looks a bit like a template, but there's #'s going on in there and a syntax I've never seen before in C++. Either use an alternative macro processor (m4 is the standard recommendation on Unix-like systems), or go about things differently. Pound sign on a Mac. What’s the best way to use VIA to help me type a pound (£) symbol? I tried to set a macro but couldn’t get it to work. hvtz pkxq pxbhr lnyyj tktz aqswn hzat nmcd ueyxcwd cerrcq cptj vsf tha uncbff avwabac