export declare function resolveUrl(url: string, base: string): string;
/**
 * Unwraps a value if it is a function, otherwise returns the value directly.
 * Useful for allowing values to optionally be specified as functions.
 */
export declare function unfunc<T, V>(value: T | ((ref: V) => T), ref: V): T;
export declare const pick: <T, K extends keyof T>(obj: T, props: K[]) => Pick<T, K>;
export declare function isNumber(x?: unknown): x is number;
/**
 * 32-bit FNV-1a hash function
 */
export declare function createHash(str: string): number;
/**
 * Utility functions for base64 encoding and decoding strings and objects.
 */
export declare const b64: {
    encode: (str: string) => string;
    decode: (str: string) => string;
    serialize: (obj: Record<string, unknown>) => string;
    parse: (encoded: string) => Record<string, string>;
};
export declare function isBrowser(): boolean;
export declare function onLine(): boolean;
export declare function isIOS(): boolean;
export declare function osVersion(): string;
export declare function compareVersions(a: string, b: string): number;
export declare function isBadIOS(): boolean;
/**
 * [Big files upload error with iOS](https://github.com/kukhariev/ngx-uploadx/issues/316)
 * TODO: move to app
 */
export declare const iosOverride: {
    chunkSize: number;
    retryConfig: {
        shouldRetry: () => boolean;
    };
} | {
    chunkSize?: undefined;
    retryConfig?: undefined;
};