import { ValueSet } from './value';
/**
 * Checks if the given value is not empty.
 * @private
 * @param a A value.
 * @returns `true` if the given value is not `undefined`, `null`, `''`, `[]` or `{}`; `false` otherwise.
 */
export declare const empty: (a: unknown) => boolean;
/**
 * Checks whether the given values are equal.
 * @public
 * @param a A value.
 * @param b A value.
 * @returns `true` if the given values are equal, `false` otherwise.
 */
export declare const equals: (a: unknown, b: unknown) => boolean;
/**
 * Calculates the differences between the two given objects and returns two objects containing the differences in each relative to the other.
 *
 * For each key that holds a different value in the two objects, the resulting objects will contain the differences in the values under that key.
 *
 * This function is recursive, that is, if the value under the key is an object, the function will be applied to that value recursively.
 *
 * @public
 * @param a An object.
 * @param b An object.
 * @returns A tuple of two objects with each containing the keys that have a different value in the corresponding argument compared to the other argument.
 */
export declare const diff: (a: {
    [key: string]: unknown;
}, b: {
    [key: string]: unknown;
}) => [{
    [key: string]: unknown;
}, {
    [key: string]: unknown;
}];
/**
 * Calculates the differences between the two given values of a valueset and returns two objects containing the differences in each relative to the other.
 *
 * @param a An object.
 * @param b An object.
 * @param valueSet A ValueSet to use as reference for the keys and types of each property.
 * @returns A tuple of two objects with each containing the keys that have a different value in the corresponding argument compared to the other argument.
 */
export declare const diffProperties: (a: {
    [key: string]: unknown;
}, b: {
    [key: string]: unknown;
}, valueSet: ValueSet) => [{
    [key: string]: unknown;
}, {
    [key: string]: unknown;
}];
/**
 * Checks if the given value is an object.
 * @public
 * @param x A value.
 * @returns `true` if the given value is an object, `false` otherwise.
 */
export declare const isObject: (x: unknown) => boolean;