/**
 * @license
 * Copyright Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
/** @fileoverview Internal implementations of SafeHtml. */
import { UnwrapType } from './trusted_types.js';
import { TrustedHTML } from './trusted_types_typings.js';
import '../environment/dev.js';
/**
 * String that is safe to use in HTML contexts in DOM APIs and HTML documents.
 *
 * @final
 */
export declare class SafeHtml {
    private readonly privateDoNotAccessOrElseWrappedHtml;
    private constructor();
    toString(): string;
}
/**
 * Builds a new `SafeHtml` from the given string, without enforcing
 * safety guarantees. It may cause side effects by creating a Trusted Types
 * policy. This shouldn't be exposed to application developers, and must only be
 * used as a step towards safe builders or safe constants.
 */
export declare function createHtmlInternal(value: string): SafeHtml;
/**
 * An empty `SafeHtml` constant.
 * Unlike the functions above, using this will not create a policy.
 */
export declare const EMPTY_HTML: SafeHtml;
/** Checks if the given value is a `SafeHtml` instance */
export declare function isHtml(value: unknown): value is SafeHtml;
/**
 * Returns the value of the passed `SafeHtml` object while ensuring it
 * has the correct type.
 * Using this function directly is not common. Safe types are not meant to be
 * unwrapped, but rather passed to other APIs that consume them, like the DOM
 * wrappers in safevalues/dom.
 *
 * Returns a native `TrustedHTML` instance typed as {toString(): string} or a string if Trusted Types are disabled.
 */
export declare function unwrapHtml(value: SafeHtml): UnwrapType<TrustedHTML> | string;