<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Aug 2, 2016, at 10:24 AM, David Majnemer via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" class="">llvm-dev@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Hello,<div class=""><br class=""></div><div class="">Today we hit another VS 2013 breakage <<a href="http://lab.llvm.org:8011/builders/sanitizer-windows/builds/26666/steps/run%20tests/logs/stdio" class="">http://lab.llvm.org:8011/builders/sanitizer-windows/builds/26666/steps/run%20tests/logs/stdio</a>> which results us having to alter LLVM.</div><div class=""><br class=""></div><div class="">While we have no documented policy of supporting two version of MSVC, we do have an informal agreement that we should support the last two versions.</div><div class=""><br class=""></div><div class="">I suggest that we alter our informal policy to the following:</div><div class=""><br class=""></div><div class="">"If a compiler version keeps getting in the way and a newer compiler is available, we should ask people to upgrade to that newer compiler."<br class=""></div><div class=""><br class=""></div><div class="">If we can support ten versions of MSVC with little burden, I don't see a reason why we shouldn't.</div><div class=""><br class=""></div><div class="">But if we find ourselves in a situation where asking folks to upgrade to a compiler which has been widely deployed soothes development for the greater LLVM community, we should consider dropping support for the older versions of that compiler.</div><div class=""><br class=""></div><div class="">In this case, dropping VS2013 allows us to use more C++11 features with confidence. Notably, move constructors will be synthesized instead of having to be manually written (and kept in sync with data members getting added).</div><div class=""><br class=""></div><div class="">What do you all think? Are folks still stuck on VS2013?</div></div></div></blockquote><div><br class=""></div><div>I think in the end it comes down to a tradeoff between the added value of what features we gain by dropping an old compiler (MSVC, GCC, Clang…) compared to its user-based.</div><div><br class=""></div><div>For example I believe last time we dropped an MSVC release we had a fairly large list of features: <a href="http://lists.llvm.org/pipermail/llvm-dev/2014-August/075869.html" class="">http://lists.llvm.org/pipermail/llvm-dev/2014-August/075869.html</a></div><div><br class=""></div><div>What is the list of features for dropping VS2013?</div><div><br class=""></div><div>(I don’t know about how widely VS2013 is still used in the community to evaluate the other side of the balance).</div><div><br class=""></div><div>— </div><div>Mehdi</div><div><br class=""></div></div></body></html>