Compile time

[Eljay Love-Jensen]

Hi Satya,

In my experience, long compile times usually occur due to poor software 
engineering regarding the build.

For a good book on the subject, please read "Large-Scale C++ Software 
Design" by John Lakos.

For a good essay on just makefiles, please read "Recursive Make Considered 
Harmful" by Peter Miller, at 
<http://www.pcug.org.au/~millerp/rmch/recu-make-cons-harm.html>.  Many 
makefiles commit two cardinal sins:  1) build too much (thus takes too 
long), 2) doesn't build enough (thus unreliable unless a clean-build is 
done, the usual culprit being failure to track dependencies).

Some tips:
NEVER include a header file that is not needed by the compilation unit.
ALWAYS include every header file required by the source or header files.
CONSIDER using header-header files, which contain a bare bones subset of a 
header file, primarily for other header files.
CONSIDER implementing the "pimpl" pattern (pointer to implementation), to 
help disassociate the implementation from the interface and reduce often 
unnecessary "cascade recompiles".

HTH,
--Eljay