[boost] [parameter] Go C++11 and above only, or keep C++03 support?

Subject: [boost] [parameter] Go C++11 and above only, or keep C++03 support?
From: Cromwell Enage (cromwell.enage_at_[hidden])
Date: 2018-11-03 02:17:36

Hi, everyone.

The end of section 3.2.1 of the current Boost.Parameter home page tutorial
notes "that because of the forwarding problem,
parameter::parameters::operator() can't accept non-const rvalues".  I've
submitted a PR to the develop branch on GitHub that would grant
Boost.Parameter the ability to support perfect forwarding and eliminate
this issue.  However, the PR uses rvalue references (in parameter::keyword,
parameter::parameters, and the code generation macros) and variadic
templates (in parameter::parameters and the code generation macros).  With
the exception of BOOST_PARAMETER_TEMPLATE_KEYWORD, the PR would make
Boost.Parameter a C++11 library.  As a result--based on <
http://pdimov.github.io/boostdep-report/develop/parameter.html#reverse-dependencies>--the
following Boost libraries known to use Boost.Parameter would also become
C++11:

Boost.Accumulators
Boost.Convert
Boost.Graph
Boost.Heap
Boost.Log
Boost.MetaStateMachine or Boost.MSM
Boost.Parameter_Python
Boost.Signals2

I'd like to hear from everyone else, especially the maintainers and users
of these libraries, if it's okay for Boost.Parameter to go C++11 and above
only or if C++03 support is still necessary.

Cromwell D. Enage