Points’ and vertices’ indices in Geometry Nodes

I am surprised, that such essential feature not implemented or not exposed.

Indices allow to create math functions and generate many shapes. Easiest example is building 2d array. And now we need to fake indices, making them from vertex position on the line with 1 meter step. So each vertex will have same X as index.

But in case of beveled and bended curve (tube) it will not work.