[Bug]: boost.context fails in c++20 due to parse_headers

[maliberty]

What happened?

I am trying to upgrade to Boost 1.89.0.bcr.2 but I get a compile error:

external/boost.context+/include/boost/context/detail/invoke.hpp:29:19: error: no type named 'result_of' in namespace 'std'
   29 |     typename std::result_of< Fn &&( Args && ... ) >::type
      |     ~~~~~~~~~~~~~~^~~~~~~~~

result_of is removed in c++20. I am using in my .bazelrc

build --cxxopt "-std=c++20"        --host_cxxopt "-std=c++20"

I have diagnosed this to be because of parse_headers in boost.context. Boost itself will avoid including this header in c++20 but parse_headers doesn't realize that. I can workaround it with a single_version_override to do - features = ["parse_headers"], but it is ugly.

I'm not enough of a bazel expert to propose a better solution but I hope other can.

Version

Development (host) and target OS/architectures: Ubuntu 24

Output of bazel --version: bazel 8.5.0

Version of relevant rules from the WORKSPACE or MODULE.bazel file: See description

Language(s) and/or frameworks involved: c++20 and Boost

How to reproduce

See description

Any other information?

No response

[fmeum]

I would suggest sending a PR that adds a new .bcr.N version that disables the feature.