BL>   Every time I make a change in C and then run it, it has to read the
BL> headers (that haven't changed),
RM> A recognized problem, with a partial solution. Look up "headers,
RM> precompiled"".

Source: Windows/DOS Developer's Journal, April 1995.

Precompiled Headers: Friend or Foe?

  Back in my Wonder Years, poking sticks into anthills or letting a
mouse loose in class was a reliable way to provoke some entertaining
confusion. Today I've found a more socially acceptable way to
simulate an angry swarm of hornets: just put a team of programmers
in a room and tell them to decide whether or not to use precompiled
headers in their current project.
  Precompiled headers are available as an option for most PC-based
C++ compilers. But there doesn't seem to be anything approaching
universal agreement on whether they are a useful feature or simply
a marketing gimmick. I've heard programmers swear their compile times
_increased_ by 50 percent when they used precompiled headers, while
other (presumably sane) users insist their compilations run three
times faster. Where does the truth lie ?
  The truth is a little more complicated than we might like.
Precompiled headers _can_ dramatically speed up your compile times.
Likewise, they can make your compiler act as if it were keeping its
swap file on a floppy disk. Like other tools, precompiled headers
can do a lot of good, but only when you use them correctly.

3.5 pages of the concepts, whys and wherefores of precompiled
headers are then presented to those who purchased the magazine.

Regards, Brenton
@EOT:

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