On Thursday, 24 January 2019 at 09:49:14 UTC, Manu wrote:
We discussed and concluded that one mechanism to mitigate this
issue
was already readily available, and it's just that 'out' gains a
much
greater sense of identity (which is actually a positive
side-effect if
you ask me!).
You have a stronger motivation to use 'out' appropriately,
because it
can issue compile errors if you accidentally supply an rvalue.
`out` with current semantics cannot be used as drop-in
replacement for shared in-/output ref params, as `out` params are
default-initialized on entry. Ignoring backwards compatibility
for a second, I think getting rid of that would actually be
beneficial (most args are probably already default-initialized by
the callee in the line above the call...) - and I'd prefer an
explicitly required `out` at the call site (C# style), to make
the side effect clearly visible.
I'd have otherwise proposed a `@noRVal` param UDA, but redefining
`out` is too tempting indeed. ;)
