Where to place "#include" files in a distribution, and how to find them

[David Oswald]

I was tinkering with using Boost extensions in an Inline::CPP based
module. Many of the Boost extensions are "header only", which should
mean that I can simple include the appropriate headers in my
distribution. But I'm not sure where they should be placed, within
the distribution, and also not sure how to specify reliably to Perl
(and later to Inline::CPP) where to find them.

use Inline CPP => Config => AUTO_INCLUDE => qq{#include
"$some_base_dir/boost/dynamic_bitset.hpp"};

How should I detect and specify $some_base_dir in a way that is robust
and reliable?

Dave