On 03/04/12 18:56, Dave Abrahams wrote:
In order to measure the compile-time efficiency of various C++11 metaprogramming techniques, I'd like to put together a set of benchmarks, and I wanted to discuss here what kinds of tests might be appropriate. Aleksey and I came up with some benchmarks for an appendix to http://boostpro.com/mplbook/, but some of those are lost and they're all getting a bit crusty. Certainly, I have no confidence that they are realistic or useful. If anyone has ideas about this, I'd be very glad to hear them.
I can't suggest a particular benchmark, but I will say that these days I find compile-time memory usage a bigger problem than compile-time runtime when it comes to complex metaprograms. So, whatever benchmarks you do, please include memory usage statistics too. In particular, I was hoping that constexpr would help in this case because it wouldn't be memoized like templates are, but I believe gcc at least has chosen to implement constexpr with memoization, so I guess it won't be more than a constant factor better. John Bytheway