On Wednesday, 1 May 2024 at 01:09:33 UTC, Liam McGillivray wrote:
This is presumably such a common task that I'm surprised it
isn't easy to find the answer by searching;
Is there a standard library function that removes all elements
from a dynamic array that matches an input argument?
In `std.array` there's the `replace` function which is supposed
to replace all occurrences that match an input with another. It
seems to work as described on strings, but I get compiler
errors when using it on other array types. I've tried using it
to replace occurrences of a certain object in an array with
`[]` in order to remove all occurrences, but it's not allowed.
Is there a Phobos function that does what I want? It would be
crazy if there isn't.
`remove`
https://dlang.org/phobos/std_algorithm_mutation.html#remove
```d
arr = arr.remove!(v => shouldBeRemoved(v));
```
Why the reassignment? Because `remove` removes elements *in
place*, and does not change the range extents. It returns the
portion of the range that contains the unremoved elements.
So to give an example:
```d
auto arr = [1, 2, 3, 4, 5];
auto result = arr.remove!(i => i % 2 == 1); // remove odd elements
assert(result == [2, 4]);
// first 2 are the slice that is stored in result
// the last three are leftovers.
assert(arr == [2, 4, 3, 4, 5]);
```
-Steve
