/**
 * Matches a case-insensitive literal string.
 *
 * @template S The string to match.
 * @example CaseInsensitive<'FOO'> // 'foo' | 'Foo' | 'fOO' | 'FOO' ...
 */
type CaseInsensitive<S extends string> = S extends `${infer L}${infer R}` ? `${Lowercase<L>}${CaseInsensitive<R>}` | `${Uppercase<L>}${CaseInsensitive<R>}` : S;

export type { CaseInsensitive };