@orta sorry to bug you, but can i ask a typescript question? i have an array of `{id: string}[]` values, but i want to extract _just_ the ids from all the objects so i have some type that's like `typeof arr[number]['id']` but i don't want just `string`, i want the all the literal keys in the array of objects. what's the magic search term i'm looking for? is this possible with mapped types? thanks for any help. here's a playground https://www.typescriptlang.org/play/?jsx=0#code/C4TwDgpgBAShDGUC8UDeAoKUCWATAXFAM7ABO2AdgOYDcmUA9A1APbAAWEpUA1hCESidS0YCxboAvnXTwWFElBFzSuIoTjwA2gF1kULajyEA5ADNxJyQBo0xqCYBGAQ1JWd6dEygdsgv1AAVgCuiiYk5NQmUI7BwDgmuFAANth8OPHYZhlQAO5c0OaWUAA+Di5u6KCQUABqzqm4AJIAIoIo1RAs2cosqkRaFMEAto5cOlomeCY6Mt54EA3JID7sAbkswclJXKR9rHGy8oouzQR1DXit7eXOAF4mNEA

@nsfmc You want "as const" to force the literal strings in the records, then "satisfies Rec[]" instead of setting the type as the version with no literal strings

https://www.typescriptlang.org/play/?jsx=0#code/C4TwDgpgBAShDGUC8UDeAoKUCWATAXFAM7ABO2AdgOYDcmUA9A1APbAAWEpUA1hCESidS0YCxboAvnXTwWFElBFzSuQSgDaqPIQDkAM3G7JAGjQ6ougEYBDUsYC6UG4LkLgxG8GxF92CIJw8BpO6OhMUBw+OIIAVgCuirok5NS6UFbxHti6uFAANth8ONn6JVAA7lzQBkZQAD6WtvbooJBQAGo2hbgAkgAi6pHgECxlyiyqRBoU8QC2VlwOGrp4ug4yEXgQ3fkgkezRFSzx+XlcpJOsWbLyirZ9BJ3deAND1jYAXro0QA