On Mon, Jun 13, 2011 at 2:41 PM, Robert Ramey <ramey@rrsd.com> wrote:
I'm trying to implement concept checking for at least parts of the boost::fusion library. My motivations are several:
a) I'm interested in making another library/program based on fusion and I believe that having implemented concepts will make this job easier.
b) I'm interested in the concept checking concept and this is way to pracitice.
Attached is the current state of my efforts. I have a few problems with this. I think most of these are specific to fusion but maybe not.
[...]
b) lines 34-38 illustrate a different problem. I can't figure out what distance(i,j) is supposed to return. I would think that result_of::distance(i, j) should be a signed integer of some sort. So I'm not understanding why this assertion traps. I not sure if it's a side effect of the problem cited in a) above.
Just quickly addressing this and only this, without looking at the referenced lines: I would think distance(i,j) would be a Boost.MPL integral constant. - Jeff