What's the deal with "Warning: explicit element-wise assignment..."

[Andrei Alexandrescu via Digitalmars-d]

On 4/15/14, 2:18 AM, bearophile wrote:
> The idea is to tell well apart the assignment of values (like scalars
> and fixed size arrays) from slice assignments. In general if you have a
> vector operation, use a []. There are corner cases (with arrays of
> arrays, fixed sized arrays of dynamic arrays, etc), that if you don't
> use such strict syntax, lead to undefined (ambiguous, weird) situations.
> The warning helps avoid that problem, and the warning will be replaced
> by a deprecation later.

This doesn't quite explain much. -- Andrei