How to filter an array so the result is an array again?

2011-09-15 Thread Cheng Wei 
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.

Re: How to filter an array so the result is an array again?

2011-09-15 Thread Cheng Wei 
Sorry, the 'for' should be 'foreach'.

Re: How to filter an array so the result is an array again?

2011-09-15 Thread Jonathan M Davis 
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