Generality creep

[Andrei Alexandrescu]

On 3/28/19 9:04 AM, ag0aep6g wrote:
> On 28.03.19 13:37, Andrei Alexandrescu wrote:
>> The conclusion is not to operate such changes everywhere (i.e. reason 
>> by analogy). The right conclusion is that save() is unnecessarily 
>> general and underspecified.
> 
> If you want to resolve the issue by amending the definition of ranges, 
> that's very fine with me. I'd much prefer that solution over going 
> through all of Phobos.
> 
> But if you focus on `save`, you're missing the point of issue 18657, 
> which is opAssign. A range can have a misbehaving opAssign without being 
> a forward range.

Then some ranges are not meant to be assignable.