Re: [Boost-users] Turning Boost.Multi-Index ordered_non_unique index into ordered_unique one, with custom comparator

On Thu, Mar 3, 2016 at 2:06 PM, Joaquin M LópezMuñoz wrote:

Dominique Devienne writes:

...

On Thu, Mar 3, 2016 at 10:21 AM, Joaquin M LópezMuñoz

[...]

struct entry { int uid; // real uuid in reality, but enough for our needs here int occurence; // the field to be indexed, uniquely "except for -1" };

OK, yes, we can do something with that. What you want is unique sorting by occurrence, except when occurrence==-1 in which case you want to (uniquely) sort lexicographically on uid. This *is* indeed a SWO, [...]

Thank you for confirming what I suspected. [...] Thanks to the overloads of entry_occurrence_less::operator()

we can lookup by occurrence as if we were using member:

This is the part I was missing, and struggling with. Seems simple, in hindsight :)

I think this suits exactly your needs, please report back otherwise.

Thank you so much for your help Joaquin. (and for BMI of course! My favorite container!!!) This is exactly what I was looking for. Encore merci, --DD