Jarrett Billingsley wrote:
On Fri, Oct 9, 2009 at 3:49 PM, Andrei Alexandrescu
<seewebsiteforem...@erdani.org> wrote:
Thanks!
I plan to add more text at the end of the chapter that discusses the
opportunities of CTFE. Walter revealed to me that CTFE, particularly now
after it's been improved by leaps and bounds by Don and by Walter himself,
could obviate a lot of the traditional metaprogramming techniques developed
for C++.
One question that bugs me is, where do you draw the line? Say there's a
metaprogramming problem at hand. How to decide on solving it with CTFE vs.
solving it with templates? It would be great to have a simple guideline that
puts in contrast the pluses and minuses of the two approaches.
It is quite possible that templates get relegated to parameterized functions
and types, whereas all heavy lifting in metaprogramming should be carried
with CTFE.
God, I wish we had a real forum with table capabilities. I can't even
rely on monospaced fonts..
Where templates win at metaprogramming:
Templates have pattern-matching capabilities for picking apart types.
CTFE is forced to reimplement part of the D lexer/parser to do so (and
combined with buggy/incompletely specified .stringof, you can't really
depend on your parsing to work right).
CTFE doesn't mean "string mixins using CTFE".
It just means CTFE. (BTW you can do string mixins with templates only,
no CTFE, if you are completely insane).
