The standard library std.algorithm is based on Range. So if
a = [1, 2, 3, 4];
auto r = filter!("a < 2")(a);

Here, r is a range.
How about I want an new array? Is there any easy way to convert the
result to array?

If we have to do like:
int[] b;
for (v; r) {
    b ~= v;
}

Then maybe it is easier to not use filter at all as:
int [] b;
for (v; a) {
   if (v < 2) b ~= v;
}

Thanks a lot.

Sorry, the 'for' should be 'foreach'.

On Friday, September 16, 2011 04:04:39 Cheng Wei wrote:
> The standard library std.algorithm is based on Range. So if
> a = [1, 2, 3, 4];
> auto r = filter!("a < 2")(a);
> 
> Here, r is a range.
> How about I want an new array? Is there any easy way to convert the
> result to array?
> 
> If we have to do like:
> int[] b;
> for (v; r) {
>     b ~= v;
> }
> 
> Then maybe it is easier to not use filter at all as:
> int [] b;
> for (v; a) {
>    if (v < 2) b ~= v;
> }

Use std.array.array.

auto a = [1, 2, 3, 4];
auto r = array(filter!"a < 2"(a));

- Jonathan M Davis