On Tuesday, 17 December 2019 at 07:40:28 UTC, AlphaPurned wrote:
if arr is a single array the follow code works(removing [i])
but if it is a double array it fails. arr as type double[A][B].
arr[i] has type double[A].
v ~= arr[i].map!(a=>to!string(a)~",").join;
with `Range = double[21]`
must satisfy the following constraint:
` isInputRange!(Unqual!Range)`
The problem isn't that it's a multi-array but that it's a
fixed-size array. As the error suggests: it complains about a
double[21], and not about a double[][]
Fixed size arrays you need to slice to make them valid input
ranges. (std.container.array is the same.)
At a terminal:
$ rdmd --eval 'int[3] x; x.map!"a+1".writeln'
...
with Range = int[3]
whose parameters have the following constraints:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> isInputRange!(Unqual!Range)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tip: not satisfied constraints are marked with >
$ rdmd --eval 'int[3] x; x[].map!"a+1".writeln'
[1, 1, 1]
Note the [] in x[].map
