Cannot writeln entire object when mixing zip/map #467
Description
The code below calls byDim on a matrix and then zips it with a vector. I then call map on the combined group (in this case, I reduced it to remove what I was actually doing with it, the code originally was subtracting values of mu from each column).
If I try to print Z[0] or Z[1], I don't have any problems, but if I try to print Z itself, then I get a long error message that starts with a complaint that generating an inout copy constructor failed. I don't have the same problem with Y, suggesting this might be the result of the interaction with zip and map together.
/+dub.sdl: dependency "mir-algorithm" version="*" +/ import mir.ndslice.allocation: mininitRcslice; import mir.ndslice.topology: byDim, map, zip; import std.stdio: writeln; void main() { static immutable a = [0.07, 0.125]; static immutable b = [[-0.1667, -0.1365], [-0.0446, 0.1997], [ 0.0764, 0.3813], [ 0.3230, 0.2999], [-0.0507, -0.2872], [ 0.0130, 0.0975], [ 0.0227, 0.0560], [ 0.0595, 0.1658], [ 0.0374, 0.1834], [ 0.1034, 0.2740]]; auto mu = mininitRcslice!double(2); auto X = mininitRcslice!double(10, 2); mu[] = a; X[] = b; auto Y = X.byDim!1.zip(mu); auto Z = Y.map!((a, b) => a); writeln(Z[0]); //works writeln(Z[1]); //works writeln(Z); //fails with long error message }