Linear array to matrix

[MoonlightSentinel]

On Saturday, 4 April 2020 at 09:25:14 UTC, Giovanni Di Maria 
wrote:
> Is there a Built-in function (no code, only a built-in function)
> that transform a linear array to a Matrix?

You can combine slide [1] and array [2]:

import std;

void main()
{
     auto input = [10,20,30,40,50,60,70,80,90,100,110,120];
     auto output = input.slide(3, 3).array;

     writeln(input);
     writeln();
     writeln(output);
}

Note that output is a view of input and not a copy.

[1] https://dlang.org/phobos/std_range.html#.slide
[2] https://dlang.org/phobos/std_array.html#.array