[Boost-build] Threading feature default

Subject: [Boost-build] Threading feature default
From: Ian Emmons (ian_at_[hidden])
Date: 2018-08-30 13:16:46

What is the default for the <threading> feature, "single" or "multi"?  I 
would actually like to know the answer to this in two contexts:

1. For Boost.Build in general (i.e., as a general build tool that I use 
for my own projects), and

2. In the build infrastructure of the Boost libraries themselves?

Thanks,

Ian