...

arr a(boost::extents[ arr::extent_range(1, 1) ]);

I'm not a multi.array user, but this is an invalid range. See Table 4 [1] Invariants: o Valid range [a.begin(),a.end()) is a valid range.

Thanks. It looks like I have misunderstood the extent_range ctor semantics. Upon re-reading the multi_array reference page in its extent_range section, I see extent_range(index start, index finish) This constructor defines the half open interval [start,finish). The expression finish must be greater than start. (I assumed that finish is included in the interval, hence the snippet.) Vassilii