MSVC 19.0 is buggy enough that I for one have spent multiple days reworking code that is fine for all other compilers we test against. Most recently in the context of https://github.com/apache/arrow/pull/10793 (ARROW-13482) I found that for some types T, `std::is_convertible<T, T>::value` will be false. This necessitated the following (very hacky) workaround:
https://github.com/apache/arrow/pull/10793/commits/c44be29686af6fab2132097aa3cbd430d6ac71fe (Side note: if anybody has a better solution than that specific hack, please don't hesitate to comment on the PR.) Would it be allowable for us to drop support for this compiler? IIUC Microsoft is no longer accepting feedback/bug reports for VS2017, let alone VS2015. Are there any users who depend on libarrow building with that compiler?
