/**
 * Use to ensure that switches are checked to be exhaustive at compile time
 *
 * @example Basic usage
 * ```typescript
 * enum Something {
 *  left,
 *  right,
 * };
 * const something = getSomething();
 * switch (something) {
 *  case Something.left:
 *    ...
 *  case Something.right:
 *    ...
 *  default:
 *    assertExhaustive(something);
 * }
 * ```
 *
 * @param x - The param on which the switch operates
 */
export declare function assertExhaustive(x: never): never;
export declare function assert(condition: boolean, reason?: string): asserts condition;
/**
 * Check the all elements of a `collection` satisfy the `premise`.
 * If any of the items fail the `premise`, returns false;
 * @returns null if the `collection` is empty, boolean otherwise
 */
export declare function allSatisfy<T>(collection: Iterable<T>, premise: (arg: T) => boolean): boolean | null;