/**
 * Collection of assert functions that not only throw errors at runtime, but
 * also work as assertions in TypeScript. Use this module by importing from
 * `@sirpepe/shed/assert`.
 */
import type { Primitive } from "./types";
/**
 * Throws an exception when the first argument is null or undefined. The second
 * argument can be used to customize the exception, but is entirely optional.
 * This function works as a type assertion in TypeScript and is the inverse of
 * `assertIsNot()`.
 *
 * Example:
 *
 * ```typescript
 * assertIs(42, "Oops"); // nothing happens
 * assertIs(null, , "Oops"); // Error: "Oops"
 * ```
 */
export declare function assertIs<T>(x: T | undefined | null, msg?: string): asserts x is T;
/**
 * Throws an exception when the first argument is not null or undefined. The
 * second argument can be used to customize the exception, but is entirely
 * optional. This function works as a type assertion in TypeScript and is the
 * inverse of `assertIs()`.
 *
 * Example:
 *
 * ```typescript
 * assertIsNot(null, , "Oops"); // nothing happens
 * assertIsNot(42, "Oops"); // Error: "Oops"
 * ```
 */
export declare function assertIsNot<T>(x: T | undefined | null, msg?: string): asserts x is undefined | null;
/**
 * Throws an exception when the first argument is not not a primitive. The
 * second argument can be used to customize the exception, but is entirely
 * optional. This function works as a type assertion in TypeScript.
 *
 * Example:
 *
 * ```typescript
 * assertIsPrimitive(null, , "Oops"); // nothing happens
 * assertIsPrimitive([42], "Oops"); // TypeError: "Oops"
 * ```
 */
export declare function assertIsPrimitive(x: any, msg?: string): asserts x is Primitive;