Boost.Build - #include <> vs. ""

From: williamkempf_at_[hidden]
Date: 2001-07-13 10:00:26

I've just noticed something strange using the Boost.Build system.  
Used to be when I changed a header file in Boost.Threads the build 
system realized this and forced a compile for any source files that 
included them.  Today I noticed that this was no longer working.  
With a little experimentation I discovered that when the header is 
included with quotes ("") it considered it a dependency but when 
included with angle brackets (<>) it wasn't.  I don't know if this 
changed in the Boost Jam stuff or changed because we've switched to 
using FTJam, so I don't know the cause of this change.

In any event, this has me wondering about the include policy for 
Boost and whether or not Boost.Build should behave this way.  As a 
VC++ programmer this is the behavior I typically deal with from the 
IDE (where <> includes are not considered dependencies), and it 
supports the specific semantics of the two include types used by my 
compiler.  However, these semantics are not portable, and I wonder 
about the impact for both our guidelines and for how the build stuff 
works.  With the current guidelines of using <> for all Boost 
includes the behavior of the build stuff is a bad thing.  However, 
the behavior may also be more compelling reason to change the policy 
for Boost code.

Thoughts?

Bill Kempf