Update following an email by Brian Ripley. The library is now compiled without
forcing c++11, but boost uses features that were deprecated in later versions.
As suggested by Ripley, we now add the -D_HAS_AUTO_PTR_ETC=0 include flag to
disable the problematic parts.
- CRAN win builder (release)
- Windows Server 2019 (release)
- macOS (release)
- ubuntu 20.04 (release, oldrel, devel)