transposed problem

[bearophile via Digitalmars-d-learn]

Is this another bug in std.range.transposed?


void main() {
     import std.stdio, std.algorithm, std.range;
     auto M = [[[1, 2]], [[3, 4]]];
     M.filter!(r => r.dup.transposed.walkLength).writeln;
     M.filter!(r => r.transposed.walkLength).writeln;
}


Output with the latest dmd:

[[[1, 2]], [[3, 4]]]
[[[]], [[]]]


Bye,
bearophile