import type { AnyCaller } from "./function.js";
/** Function that always returns null. */
export declare function getNull(): null;
/** Nullable is the value or `null` */
export type Nullable<T> = T | null;
/** Is a value null? */
export declare function isNull(value: unknown): value is null;
/** Assert that a value is not null. */
export declare function assertNull<T>(value: Nullable<T>, caller?: AnyCaller): asserts value is T;
/** Is a value not null? */
export declare function notNull<T>(value: Nullable<T>): value is T;
/** Assert that a value is not null. */
export declare function assertNotNull<T>(value: Nullable<T>, caller?: AnyCaller): asserts value is T;
/** Get the not-nullish version of value. */
export declare function requireNotNull<T>(value: Nullable<T>, caller?: AnyCaller): T;
/** Nullish is the value or `null` or `undefined` */
export type Nullish<T> = T | null | undefined;
/** Is a value nullish? */
export declare function isNullish<T>(value: Nullish<T>): value is null | undefined;
/** Assert that a value is not nullish. */
export declare function assertNullish<T>(value: Nullish<T>, caller?: AnyCaller): asserts value is T;
/** Is a value not nullish? */
export declare function notNullish<T>(value: Nullish<T>): value is T;
/** Assert that a value is not nullish. */
export declare function assertNotNullish<T>(value: Nullish<T>, caller?: AnyCaller): asserts value is T;
/** Get the not-nullish version of value. */
export declare function requireNotNullish<T>(value: Nullish<T>, caller?: AnyCaller): T;