On 2019-03-24 19:40 +0000, Jonny Grant wrote: > Can I ask, for this nonnull attribute, would it also detect for > std::cin, std::err, std::clog as well as std::cout ? Worth adding for > std::wcin, std::wcout, std::cerr, std::wclog too. Adding this attribute to basic_ostream will cover std::cout, std::clog, std::cerr etc. For input streams we can't do that because: char *useless = nullptr; cin >> useless; // expect EOF here is perfectly valid when cin reaches EOF (for e.g. though this code seems stupid). > Are there other places where nullptr would not be valid? There are lots > of classes, eg <streambuf> Adding this for basic_ostream also applies to ostringstream because it inherits basic_ostream. Unfortunately Marc just told me nonnull is also an optimization attribute. So adding it would optimize the null check in operator<< away. Maybe we need a new attribute? Called "warn_if_null"? -- Xi Ruoyao <xry111@xxxxxxxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
