Given the patch @seantalts made to the Math library (thanks!), I’d like us to consider releasing a new version of the library soon. If users are seeing runtimes of 1/4 relative to v2.17.0, then I think it’s probably well worth the effort. We don’t really need to patch anything else; there’s also no backwards incompatibility.
I’d say it’s probably a good idea. There is one bug that I found in the development version of CmdStan that wasn’t in the 2.17.0 release version, but that’s a somewhat separate issue from the Stan library itself.
If the 2.17.1 release = master + 1 commit, I think it is fine. Some other stuff has been merged into develop that requires C++11, so that should wait for 2.18.x.
I like your point, @bgoodri… but I can’t compile RStan 2.16 without a C++11 capable compiler. This may not be true for cmdstan, but in practice the 2.16 RStan release is already a C++11 beast. I have g++ 4.6 and Intel 2015 compilers; none of them worked. Only a g++ 6.3 got me RStan 2.16 building.
Can’t we just revert 1 commit from master? I think @wds15 is experiencing a problem where I accidentally made StanHeaders 2.16 use a C++11 construct that isn’t present in StanHeaders > 2.16.