/**
 * Checks if `value` is an object and if it's not an Array.
 *
 * @param value The value to check.
 * @returns Returns true if `value` is an object and if it's not an Array, else `false`.
 */
export declare function isSimpleObject(value?: any): boolean;
/**
 * Performs a deep merge (recursively) of objects from `source` to `target`.
 * Does modify objects and replace arrays.
 * Copies the values of all of the enumerable own properties from `source` to `target` object.
 *
 * @param target The target object to copy to.
 * @param source The source object from which to copy properties.
 * @example
 *
```
const target = {
  "a": 1,
  "b": 1,
  "c": { "x": 1, "y": 1 },
  "d": [ 1, 1 ],
  "f": "test",
  "g": [ "test1", "test2" ]
};
const source = {
  "b": 2,
  "c": { "y": 2, "z": 2 },
  "d": [ 2, 2 ],
  "e": 2,
  "f": null
};
const merged = mergeDeepOnTarget(target, source);

// Results
{
  "a": 1,
  "b": 2,
  "c": {
    "y": 2, "z": 2, "x": 1
  },
  "d": [ 2, 2 ],
  "e": 2,
  "f": null,
  "g": [ "test1", "test2" ]
}
 * ```
 */
export declare function mergeDeepOnTarget(target: any, ...sources: any[]): void;