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Section: 30.4.3 [narrow.stream.objects] Status: NAD Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2017-02-03
Priority: Not Prioritized
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Section 27.3.1 says "After the object cerr is initialized, cerr.flags() & unitbuf is nonzero. Its state is otherwise the same as required for ios_base::init (lib.basic.ios.cons). It doesn't say anything about the the state of clog. So this means that calling cerr.tie() and clog.tie() should return 0 (see Table 89 for ios_base::init effects).
Neither of the popular standard library implementations that I tried does this, they both tie cerr and clog to &cout. I would think that would be what users expect.
The standard is clear as written.
27.3.1/5 says that "After the object cerr is initialized, cerr.flags() & unitbuf is nonzero. Its state is otherwise the same as required for ios_base::init (188.8.131.52)." Table 89 in 184.108.40.206, which gives the postconditions of basic_ios::init(), says that tie() is 0. (Other issues correct ios_base::init to basic_ios::init().)