Are you saying decent code avoids indexing into arrays? Or are you saying it avoids doing so without certainty the bounds checks will succeed?

Decent code generally avoids indexing into arrays at all; if it does so then it does so in ways where the bound checks are so certain to succeed that you can usually explain it to the compiler (e.g. split an array into slices and access those slices).

that is what I thought you were saying, and it doesn't make much sense to me. AFAICT the point of arrays as a data structure is to allow relatively cheap indexing at the cost of more expensive resizing operations. What else would you do with an array other than index into it?

> e.g. split an array into slices and access those slices

How is this not indexing with a little abstraction? Aren't slices just a way of packaging an array with a length field it a standard way? I'm not aware of many array implementations without a length (and usually also capacity) field somewhere , so this seems like a mostly meaningless distinction (ie all sclices are arrays, right).

> AFAICT the point of arrays as a data structure is to allow relatively cheap indexing at the cost of more expensive resizing operations. What else would you do with an array other than index into it?

The main thing you do with arrays is bulk operations (e.g. multiply it by something), which doesn't require indexing into it. But yeah I think they're a fairly niche datastructure that shouldn't be privileged the way certain languages do.

> How is this not indexing with a little abstraction? Aren't slices just a way of packaging an array with a length field it a standard way?

Sure (well, offset and length rather than just a length) but the abstraction is safe whereas directly indexing into the array isn't.