On Thursday, 30 April 2015 at 02:44:22 UTC, Steven Schveighoffer
wrote:
On 4/29/15 8:35 PM, Martin Nowak wrote:
Occasionally I'm using if (auto ary = func()), despite the
fact that the
semantics are wrong, but it's nice and short and works as long
a func
always returns null instead of empty slices.
I wonder if it's possible to fix this, as it is, IMO, the only
legitimate drawback of this change. Could we make the following
work?
if((auto ary = func()).length)
Another thing to consider is how this is a general problem. It's
not that atypical to want to declare a variable in the if
condition and then use a function call on it for the actual
condition, which it looks like your suggestion would work with,
but if we consider a solution like that, I think that we need to
consider the general case and not just checking for length on
arrays.
Another syntax might be something like
if(auto ary = func(); ary.length)
and make it similar to how for loops work. That would also allow
you to check stuff other than what the variable gets initialized
with or to use it in a more complicated expression. e.g.
if(auto ary = func(); foo(ary))
It's also arguably more consistent with other language features.
But regardless, the general idea of what you're proposing could
provide some good syntactic sugar.
- Jonathan M Davis
