the pros and cons of "catch-all" header files

["Robert P. J. Day" <rpjday@mindspring.com>]

  over the next few days, i'm going to have some general design-type
questions as i try to restructure a project i'm working on, so i'm
hoping i don't wander too far from the mandate of the list.

  on this current project, there is frequent use of what i call
"catchall" header files.  rather than have individual source files
pull in just those header files they need, a monster "catchall.h" file
is created that contains almost all project-related inclusions, so
that source files need only:

  #include "catchall.h"

  sure, it's convenient, but there are also some obvious downsides.
the simple question -- is there a defensible rationale for this
approach?  i personally don't like it and would prefer source files to
be more selective, but the argument i keep hearing is, "it's more
convenient."

  thoughts?

rday