/**
 * Interface for applying properties to a target using a specific strategy
 */
export interface IMergeStrategy {
    /**
     * Apply properties from source to target for the given keys
     *
     * @param target - The construct to apply properties to
     * @param source - The property values to apply
     * @param allowedKeys - Only properties whose names are in this list will be
     * read from `source` and written to `target`. This acts as an allowlist
     * to ensure only known CloudFormation resource properties are applied.
     */
    apply(target: object, source: object, allowedKeys: string[]): void;
}
/**
 * Strategy for handling nested properties in L1 property mixins
 */
export declare class PropertyMergeStrategy {
    /**
     * Replaces existing property values on the target with the values from the source.
     * Each allowed key is copied from source to target as-is, without
     * inspecting nested objects. Any previous value on the target is discarded.
     */
    static override(): IMergeStrategy;
    /**
     * Deep merges nested objects from source into target.
     * When both the existing and new value for a key are plain objects,
     * their properties are merged recursively. Primitives, arrays, and
     * mismatched types are overridden by the source value.
     */
    static combine(): IMergeStrategy;
    private constructor();
}