[Boost-build] Overuse of jam features

From: Vladimir Prus (ghost_at_[hidden])
Date: 2007-03-19 17:26:47

Looking at python.jam, I see this:

        includes ?= [ path-to-native $(:E=python$(version):R=$(:E=include:R=$(prefix))) ] ;

and I have not the slightest clue what this is supposed to do. I suspect it
concatenates, $(prefix), "include" and "python$(version), but the meaning of $(:E) syntax
is not obvious for me, and use of nested expansions does not seem clear.

Would it be better to stay away from arcane features of bjam, rather than 
use them like that?

- Volodya