Second, I would like to know what the official conclusion would be from the Boost Committee about the license implications in cases like these. Maybe it has come up before and is well established. On the surface, the implications seems ambiguous to me when: DEVELOPER_A takes unlicensed code off the internet, prefixes it with a comment that says "Thanks to DEVELOPER_BÂ ", then prefixes the whole file with a file-level copyright notice that says "COPYRIGHTÂ DEVELOPER_A", and then says it's distributed under BSL-1.0 license, and then the boost team re-distributes the source code.
I am on record here on boost-dev on how incorrect the software which scans for "plagiarism" is. Technically, legally, and morally. Those third party audit vendors basically do almost no work, they feed the code to a plagiarism program which contains corpuses derived from various well known places on the internet in order to appear like they earned their fees. Most of said vendors never bother to review the reports of "plagiarism" they return for accuracy. The knee jerk reaction of deleting anything in those reports is just NIH syndrome in another variant. For small snippets of algorithm like you mostly get from stackoverflow, or public websites, they are uncopyrightable in any case as they are maths, which cannot be copyrighted nor patented anywhere in the world. Only the naming of variables might be copyrightable, and hence one would be wise to change the variable names. For larger snippets, fair use exception generally applies, though fair use exceptions don't exist in some jurisdictions of the Western world. The use of the phrase "taken from" in the Boost.Intrusive comment is unfortunate. "Inspired by" is much better. Doesn't affect the legality though. I think linking to source of bit tricks is very good. It helps explain the algorithm to those studying Boost code to learn from it. I think we should do more of it, not less. 99% of the C and C++ snippets on StackOverflow actually come from the book "Hacker's Delight" by Henry Warren. He explicitly says that reusing said snippets from his book require no attribution, so all those snippets on StackOverflow are legal, and so is reusing them in Boost code, with or without attribution. Last time I raised this issue, Boost decided to delete the "offending" parts rather than take a stand for what is right. I assume nothing here will change this time round, but I encourage Boost library authors to grow a backbone and stand up for good etiquette. I similarly encourage Boost users to tell management to stop implementing NIH, in all its forms. Niall