Re: a struct as an multidimensional array index

[Ali Çehreli via Digitalmars-d-learn]

On 6/10/22 01:08, Chris Katko wrote:
> Is it somehow possible to use a struct as a [multidimensional] array 
index:

You can define an opIndex that takes any index type if the array is 
defined by you:

import std.stdio;
import std.format;

struct indexedPair {
  size_t x, y;
}

struct MyArray {
  bool[3][3] elements;

  ref opIndex(indexedPair i) {
    return elements[i.y][i.x];
  }

  // void toString(scope void delegate(in char[]) sink) const {
  //   import std.algorithm;
  //   sink.formattedWrite!"%-(%-(%s %)\n%)"(
  //     elements[].map!(row => row[].map!(column => column ? 'T' : 'f')));
  // }
}

void main() {
  auto arr = MyArray();
  auto p = indexedPair(1, 1);

  arr[p] = true;
  writeln(arr);
}

I played with that toString function but for some reason it prints all 
Ts. (?)

Ali