GC blessed for C++ (again)

[jmh530 via Digitalmars-d-announce]

On Tuesday, 11 April 2017 at 16:16:03 UTC, Jack Stouffer wrote:
> On Tuesday, 11 April 2017 at 07:02:19 UTC, Swoorup Joshi wrote:
>> Breaking, you mean the standard library? or including user 
>> codebases?
>
> Taking the GC out of language constructs (e.g. ~=, AAs) would 
> be a massive breaking change and would probably break the 
> majority of D code in existence.

Is there a non-breaking way to do it that would increase the 
amount of flexibility while keeping the current behavior as a 
default? For instance, the equivalent of using 
std.experimental.allocator so that a user could switch between 
the default being GCAllocator or Mallocator, or something like 
that...