On Tuesday, 23 June 2015 at 01:07:17 UTC, Jonathan M Davis wrote:
No, you can't guarantee that an auto ref parameter won't be
mutated, but auto ref clearly indicates that you intend to
accept both lvalues and rvalues, meaning that it would be
stupid to be writing the function with the idea that you would
be passing in an argument which would be mutated. ref on the
other hand clearly indicates the intention to mutate the
argument.
- Jonathan M Davis
That is why, as a good API designer, you'd express that fact by
adding const ontop of it, i.e. const ref.
Only for the few rare cases where you need to account for
lazy-caching or similar mutating constructs, you'd be grateful to
have the nice escape hatch, plain ref.
Daniel N
