https://forum.dlang.org/post/eih04u$1463$1...@digitaldaemon.com
A version of the code that takes `T which` as a parameter instead
of `int index`.
```
// remove an item from an array
template drop(T)
{
T drop( inout T[] arr, T which )
{
int i;
T result;
for (i=0; i < arr.length; i++)
{
if (arr[i] == which)
{
result = arr[i];
break;
}
}
debug if ( which >= arr.length)
throw new Exception(str.format("Attempt to drop the %s of
value %s from an array, but it was not found.", typeid(T),
which));
}
for (; i < arr.length; i++)
{
arr[i] = arr[i + 1];
}
arr.length = arr.length - 1;
return result;
}
}
```
It has worse case complexity O(2n) = O(n) whereas the other one
can run in half as long minimally and sometimes just as long (but
still O(n)), but usually one needs to linear search for the entry
first.
