David Abrahams wrote:
I find myself creating this class member:
compressed_pair< storage , compressed_pair< Lookup , compressed_pair< GetUnstored , SetUnstored > > > members;
Just one comment here: shouldn't the storage member be in the innermost compressed_pair? Currently the innermost item compressed_pair<GetUnsorted, SetUnsorted> has two empty members and so isn't actually "compressed". Using: compressed_pair< empty1, compressed_pair< empty2, compressed_pair< empty3, storage> > > ensures that each compressed pair has one non-empty member and one empty member, so the final object should be just sizeof(storage). All of which suggests that a compressed-tuple would be a good idea, although ordering the items within the tuple to ensure compression is actually a larger challenge than folks may have realised. In the mean time if additional template constructors can be added, I see no problem with that. John.