[Boost-build] Using custom generators

From: John Reid (j.reid_at_[hidden])
Date: 2007-02-22 12:54:20

Suppose I have a tool that compiles files of type .g into .cpp .hpp and 
.txt files. The names of these generated files can not be determined 
from the filename of the source .g file.

I can register the .g type and create a rule and an action to run the 
tool. I am having problems using custom generators to tell boost.build 
which files the tool will generate.

I've looked at the documentation:
http://www.boost.org/doc/html/bbv2/extending/tools.html

and I figured the quickest and easiest way to do this is to define 
features that are set on each .g source file and then inspect them in 
the generated-targets rule of the custom generator. Does this sound 
sensible?

Given the above I've struggled to work out how to return appropriate 
values from the custom generator rule. The documentation does not seem 
to cover this at all. Could someone provide me with example code to 
extract a filename from a feature and build a suitable return value for 
the generated-targets rule from it?

Thanks,
John.