table.insert should return the position at which the item was inserted

[strawbberrys]

I believe it would be useful for table.insert to return the position at which the item was inserted. Currently, the position an item was inserted at with table.insert is unknown (unless using the optional position argument) which can limit its usage and cause un-needed extra code to be created. Returning the position that the item was inserted at could be very useful for many reasons.

For example, inserting an item into an array using table.insert inside of a function, then returning another function which removes that item from the array. Currently, you would have to insert the item into the array, get the length of the array via the length operator (#) and store it into a variable, then finally remove the value with that number. If this change was made, you could simply use the number returned by table.insert and avoid making any extra calls.

How it is now:

function Signal:connect(callback: (...any) -> ()): () -> ()
    assert(type(callback) == "function", "callback must be a function")

    table.insert(self._callbacks, callback)
    local position = #self._callbacks

    return function()
        self._callbacks[position] = nil
    end
end

How it would be:

function Signal:connect(callback: (...any) -> ()): () -> ()
    assert(type(callback) == "function", "callback must be a function")

    local position = table.insert(self._callbacks, callback)

    return function()
        self._callbacks[position] = nil
    end
end

I don't believe this change would have any major impact on existing code. I don't believe it has any downsides either.

[SnowyShiro]

irrelevant question to what you're asking for but wouldn't that code not work in some cases? i.e. say you made 3 connections, and then disconnected the 2nd one, when you go to disconnect the 3rd one the code would error because the 3rd connections position variable is 3, but its actual position in self._callbacks is now 2.

[strawbberrys]

You're completely right about that. A simple fix would be directly removing it instead of using table.remove, keep in mind this is just an example though. Also speaking of table.remove, it already has the same functionality I'm asking for where it returns the position at which the item was removed. I see no reason for table.insert not to share the same feature.