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- Dictionaryopt/ɒpt/
verb
- 1. make a choice from a range of possibilities: "consumers will opt for low-priced goods"
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Nov 21, 2010 · #define __in #define __out #define __in_opt Meaning they get replaced with nothing on the Preprocessor pass. Are they just a documentation method, without any functionality? If so, I can see the advantage to documenting the code in line like this. With something like doxygen you need to write out the parameter names twice.
This is part of Microsoft's Source-Code Annotation Language. _In_Opt_ means you may pass NULL. Thank you very much. Now that I have a name for these annotations (I originally thought that they were interpreted and meant something significant to the compiler), I have a starting point for further research.
Mar 23, 2012 · When you build the project with /analyze compiler option (Project Properties, Code Analysis -> General), these play important role in finding the coding issues. For example, if a particular pointer argument says __in then it must not be passed a null pointer. The function will not check for null and may cause SEH. __in_opt argument may be null.
Jul 4, 2018 · 4. The answer is yes! To the extent that you could already have recursive macros in C, you can do it in C++20 and __VA_OPT__ makes some things way, way nicer. Here's an example (with explanation) of what you can do: define a FOR_EACH macro that applies a macro to a bunch of arguments and is way nicer than the horrible things you had to do prior ...
38. In C++20, the preprocessor supports __VA_OPT__ as a way to optionally expand tokens in a variadic macro if the number of arguments is greater than zero. (This obviates the need for the ##__VA_ARGS__ GCC extension, which is a non-portable and ugly hack.) Clang SVN has implemented this feature, but they haven't added a feature test macro for ...
Feb 21, 2014 · alt is used to describe alternative scenarios of a workflow. Only one of the options will be executed. opt is used to describe an optional step in the workflow. For example, for an online shop purchase sequence diagram you may use opt to describe how the user can add gift wrapping if she wishes. alt may be used to describe two variants of ...
Mar 9, 2011 · JAVA_OPTS is the standard environment variable that some servers and other java apps append to the call that executes the java command. For example in tomcat if you define JAVA_OPTS='-Xmx1024m', the startup script will execute java org.apache.tomcat.Servert -Xmx1024m. If you are running in Linux/OSX, you can set the JAVA_OPTS, right before you ...
Apr 8, 2011 · It is possible to avoid the use of GCC's ,##__VA_ARGS__ extension if you are willing to accept some hardcoded upper limit on the number of arguments you can pass to your variadic macro, as described in Richard Hansen's answer to this question.
Nov 13, 2018 · 2-opt deletes two edges and creates two new ones (assuming the cost matrix is symmetric), so the cost function can be simplified to consider only the edges that change. For large arrays this is much faster than enumerating over the whole route.
Dec 21, 2023 · 1. Unfortunately __VA_OPT__ support in MSVC is broken in some versions of Visual Studio. I tested this with Microsoft Visual Studio 2022, version 17.8.3. Because __VA_OPT__ is a C++20 feature you will need to specify std:c++20 or later, but on my system that does not help. However if you use /Zc:preprocessor it does have some effect.
