On Mon, Jan 13, 2020 at 12:39:30PM -0500, Steven Schveighoffer via
Digitalmars-d-learn wrote:
> I have a range (array), I want to find an element and get it from that
> array.
>
> The code I'm writing looks like this:
>
> auto answer = arr.find!((item,x) => item.id == x)(id);
> enforce(!answer.empty, "id not in the range");
> auto realAnswer = answer.front;
>
> I can't do find(id).front, because that relies on asserts, which throw
> errors and kill the program, and are not always compiled in. I need an
> exception thrown so I can recover and report the error to the user.
>
> But I hate to write 3 lines of code to do this every time.
>
> I'm not seeing an easy solution in Phobos, am I missing it?
[...]
Why not write your own convenience wrapper?
auto firstElement(R)(R r)
if (isInputRange!R)
{
if (r.empty) throw new Exception(...);
return r.front;
}
auto e = myData.find!(e => blah(e)).firstElement;
T
--
I think Debian's doing something wrong, `apt-get install pesticide', doesn't
seem to remove the bugs on my system! -- Mike Dresser
