Bug 6835 – Code pattern: uniq on an array

"Given an unsorted array, remove the duplicate items" is a common need. In std.algorithm there are tools to perform this task with a very limited amount of code: import std.algorithm; void main() { auto items = [3, 1, 5, 2, 3, 1]; items.length -= copy(uniq(items.sort()), items).length; assert(items == [1, 2, 3, 5]); } (If you see better solutions feel free to add a comment.) It's a single line of code, but in my opinion it's not obvious code, and it repeats the name "items" three times (this makes it a bit bug prone). Removing the duplicated items from an unsorted array is a common operation, so maybe it's worth adding this pattern as a function, named like std.array.sortedUnique or something similar. (Other ways to create an array of unique items is to use hashing, but this is better left to other functions.)

I meant something like this: T[] unique(T)(T[] items) /*pure nothrow*/ { items.length -= items.sort().uniq().copy(items).length; return items; }