Eliminate redundancy of dup/idup

[Adam D. Ruppe]

On Sunday, 9 September 2012 at 16:25:12 UTC, Timon Gehr wrote:
>>>         c = "another"; // so this compiles
>
> This does not compile anymore now.


One option I've heard that might be OK is to make auto strip off 
the top level immutable:

immutable(char[]) a;
auto b = a; // b is immutable(char)[]
b = "test"; // allowed


This kind of thing is already done on function calls.


If you want to keep the full immutability including the top one, 
use immutable instead of auto.