DIP77 - Fix unsafe RC pass by 'ref'

[Martin Nowak via Digitalmars-d]

On Wednesday, 8 April 2015 at 23:11:08 UTC, Walter Bright wrote:
> http://wiki.dlang.org/DIP77

So someone passes an RCO via ref to avoid the inc/dec, and 
because that imposes safety issues we turn it into some sort of 
pass by value under the hood, defeating the purpose, and provide 
an opt-out via @system opAssign.

Wouldn't it more straightforward to make pass-by-ref unsafe 
(@system) for RCOs?

Then the only thing missing to make this equally powerful, would 
be an optimization opportunity for the compiler to elide copies 
of pass-by-value RCOs, e.g. it could avoid calling the postblit 
when the function retains the refcount.