On Saturday, 4 May 2013 at 21:48:25 UTC, Walter Bright wrote:
On 5/4/2013 2:22 PM, deadalnix wrote:
I still think this is inferior to Rust's solution and like to
see ref as a
equivalent of the Rust burrowed pointer. It achieve the same
safety at compile
time instead at runtime, and incurs no extra complexity except
in some very rare
cases (when you have a function taking several arguments by
ref and returning
also by ref and the lifetime of the returned ref isn't the
union of the lifetime
of the ref parameters - a very specific case).
As you say, D ref's are analogous to Rust's borrowed pointers,
and for the escaping ref problem, Rust requires additional
annotations (much like the 'scope ref' proposal).
http://static.rust-lang.org/doc/tutorial-borrowed-ptr.html#returning-borrowed-pointers
The runtime check is because Andrei & I really didn't like
requiring additional annotations.
Where you miss the point, is that these annotations may be
omitted (and they are most of the time). When nothing is
specified, the lifetime of the returned reference is considered
to be the union of the lifetime of parameters lifetime, which is
what you want in 99% of cases.
