Why C++ compiles slowly

[dsimcha]

== Quote from Walter Bright (newshound2 at digitalmars.com)'s article
> bearophile wrote:
> > And regarding the problem of searching in a sequence of items, if the
> > sequence is small (probably up to 10 or 20 if the items are integers, the
> > language is a low level one and the associative array is not very efficient),
> > a linear search or a binary search is often faster.
> Yup, and that piece of code was written in a time where there were very few
> items added into the string table. It never showed up on the radar before.

I wonder how much of the compile time of more typical projects is taken up by this
linear search.  Could it be that that's also why std.stdio compiles relatively
slow?  It's a big module that does a lot of template instantiations.  If this
silly bug was a bottleneck everywhere, then I'd love to see D vs. Go compile times
after this gets fixed.