export declare class Unreachable_Code_Path_Error {
    constructor(message: string, stack: string | undefined);
    message: string;
    stack: string | undefined;
}
/**
 * The exit code of a process that reached an unreachable code path: an implementation error.
 * It matches the exit code Node.js uses for an uncaught exception.
 */
export declare const EXIT_CODE_IMPLEMENTATION_ERROR = 1;
/**
 * Marks a code path that cannot be reached; reaching it is an implementation error.
 * In Node.js it writes the explanation and the stack to stderr and exits immediately with
 * {@link EXIT_CODE_IMPLEMENTATION_ERROR}, so that it cannot be caught and mistaken for another kind of error.
 * Elsewhere it throws an {@link Unreachable_Code_Path_Error}.
 */
export default function (explanation: string): never;