standards

I am building a class that has a union for its matrix data, however, I can only get it compile when I do not have a name for the struct\union. However, with a higher level warning level (four on visual studio) I will a warning saying warning C4201: nonstandard extension used : nameless struct/union I looked into it, and I don't seem to be able to find a way to prevent this. Anyway possible that I know of will cause a different compiler error related to the declaration of one or the other. How can I prevent getting this warning and make it conform to standards, without just disabling the

My understanding is that GREATEST() and LEAST() are not part of the SQL standard, but are very common. I'm wondering, is there a way to clone the functionality of GREATEST keeping within the SQL standard? SELECT id, GREATEST(1,2,3,4,5,6,7) AS number FROM table The fully query: SELECT SUBSTR(section,1,2) AS campus, AVG(GREATEST(maximum - enrolled, 0)) AS empty FROM sectionrun WHERE coursenumber = '105' AND subject = 'ENGL' GROUP BY campus You can use the CASE expression: SELECT SUBSTR(section,1,2) AS campus, AVG(CASE WHEN maximum - enrolled > 0 THEN maximum - enrolled ELSE 0 END) AS empty FROM

Presently I've Debian Squeeze(AMD64 linux), libstdc++5 and libstdc++6 on my computer. Do these C++ libraries conform to the ISO standard C++11? No they don't conform fully, but they have elements : C++11 support on stdlibc++ (this is for the latest version, not the one you have) C++11 support on GCC versions Your best bet is to try libc++ (developed for clang but works with GCC 4.4 as well). You could try downloading and compiling the latest clang or GCC release as well. Only MS has a fully implemented C++11 library in VC 11 (or so they claim, and yes, that doesn't help you, sorry). 来源： https:

The LLVM C++ compiler has full support for C++11 standard. Is there a way to set C++11 as the default standard without adding -std=c++11 compiler flag every time? I tried setting CCXFLAGS environment variable to -std=c++11 , but with no luck. Use clang 6.0.0 or higher. The default C++ dialect is now C++14. http://releases.llvm.org/6.0.1/tools/clang/docs/ReleaseNotes.html#c-language-changes-in-clang 来源： https://stackoverflow.com/questions/21581838/set-as-default-c11-in-clang

This question already has answers here : Closed 2 years ago . Why doesn't C provide struct comparison? (5 answers) The unavailability of structs as comparison operands is one of the more obvious things in C that don't make too much sense (to me). structs can be passed by value and copied via assignments but == is not specified for them. Below are the relevant parts of the C11 standard (draft) that define the constraints of the equality operators ( == and != ) and the simple assignment operator ( = ). Note the lack of structures and unions in the constraints of equality operators. (Apart from

I have a double containing seconds. I would like to convert this into a time_t . I can't find a standard function which accomplishes this. Do I have to fill out the time_t by hand? The type of std::time_t is unspecified. Although not defined, this is almost always an integral value holding the number of seconds (not counting leap seconds) since 00:00, Jan 1 1970 UTC, corresponding to POSIX time. So, just a safe casting between them could be fine. Also be carefull about portability (because it's type is not specified in the standard) and consider about the values than can not fit while casting