type Merged<TDestination, TSource> = TSource extends undefined ? TDestination : TDestination extends undefined ? TSource : TSource extends any[] ? TDestination extends any[] ? TDestination & TSource : TSource : TSource extends object ? TDestination extends object ? TDestination extends any[] ? TSource : TDestination & TSource : TSource : TSource;
/**
 * Recursively merges `source` into `destination` in place and returns the result.
 * - Objects are merged key by key.
 * - Arrays are merged index by index.
 * - Primitive and class-instance values replace the destination.
 * - `undefined` source values leave the destination unchanged.
 * - Circular references in `source` are silently dropped.
 *
 * Prefer `combine` for a non-mutating deep merge or `deepClone` for a simple deep copy.
 *
 * @returns The merged value — either `destination` (mutated) or `source` when they cannot be merged.
 */
export declare function mergeInto<D, S>(destination: D, source: S): Merged<D, S>;
/**
 * A simplistic implementation of a deep clone algorithm.
 * Caveats:
 * - It doesn't maintain prototype chains - don't use with instances of custom classes.
 * - It doesn't handle Map and Set
 *
 * @returns A deep copy of `value` with the same type.
 */
export declare function deepClone<T>(value: T): T;
type Combined<A, B> = A extends null ? B : B extends null ? A : Merged<A, B>;
/**
 * Performs a non-mutating deep merge of two or more values.
 * - All arguments are left unchanged; the result is always a new value.
 * - Objects are merged key by key; arrays are merged index by index.
 * - `undefined` values are skipped (they do not overwrite existing values).
 * - `null` values replace existing values.
 *
 * @returns A new deeply-merged value of the combined type.
 * @example
 * combine({ a: 1 }, { b: 2 }) // { a: 1, b: 2 }
 * combine({ a: { x: 1 } }, { a: { y: 2 } }) // { a: { x: 1, y: 2 } }
 */
export declare function combine<A, B>(a: A, b: B): Combined<A, B>;
export declare function combine<A, B, C>(a: A, b: B, c: C): Combined<Combined<A, B>, C>;
export declare function combine<A, B, C, D>(a: A, b: B, c: C, d: D): Combined<Combined<Combined<A, B>, C>, D>;
export declare function combine<A, B, C, D, E>(a: A, b: B, c: C, d: D, e: E): Combined<Combined<Combined<Combined<A, B>, C>, D>, E>;
export declare function combine<A, B, C, D, E, F>(a: A, b: B, c: C, d: D, e: E, f: F): Combined<Combined<Combined<Combined<Combined<A, B>, C>, D>, E>, F>;
export declare function combine<A, B, C, D, E, F, G>(a: A, b: B, c: C, d: D, e: E, f: F, g: G): Combined<Combined<Combined<Combined<Combined<Combined<A, B>, C>, D>, E>, F>, G>;
export declare function combine<A, B, C, D, E, F, G, H>(a: A, b: B, c: C, d: D, e: E, f: F, g: G, h: H): Combined<Combined<Combined<Combined<Combined<Combined<Combined<A, B>, C>, D>, E>, F>, G>, H>;
export {};