import * as React from 'react';
export declare type ConfigurationOverrideFunction = (a: any) => any | undefined | null;
export declare type ConfigurationOverrideObject = {
    [k: string]: any;
};
export declare type ConfigurationOverride = ConfigurationOverrideObject | ConfigurationOverrideFunction;
export declare type StyleOverride = ConfigurationOverride;
export declare type OverrideObject = {
    component?: React.ComponentType<any> | null;
    props?: ConfigurationOverride | null;
    style?: ConfigurationOverride | null;
};
export declare type Override<T = any> = OverrideObject | (React.ComponentType<any> & {
    component?: undefined;
    props?: undefined;
    style?: undefined;
});
export declare type Overrides<T = any> = {
    [x: string]: Override;
};
/**
 * Given an override argument, returns the component implementation override if it exists
 */
export declare function getOverride(_override: any): any;
/**
 * Given an override argument, returns the override props that should be passed
 * to the component when rendering it.
 */
export declare function getOverrideProps<T>(_override?: Override | null): T;
/**
 * Coerces an override argument into an override object
 * (sometimes it is just an override component)
 */
export declare function toObjectOverride<T>(_override?: Override): OverrideObject;
/**
 * Get a convenient override array that will always have [component, props]
 */
export declare function getOverrides<T = {
    [k: string]: any;
}>(_override: any, defaultComponent: React.ComponentType<any>): [React.ComponentType<any>, T];
/**
 * Merges two overrides objects – this is useful if you want to inject your own
 * overrides into a child component, but also accept further overrides from
 * from upstream. See `mergeOverride` below.
 */
export declare function mergeConfigurationOverrides(target: ConfigurationOverride, source: ConfigurationOverride): ConfigurationOverride;
export declare function mergeOverride(target: OverrideObject, source: OverrideObject): OverrideObject;
export declare function mergeOverrides(target?: Overrides, source?: Overrides): Overrides;
/**
 * Merges two override objects using the following behavior:
 * - Component implementation from the source (parent) replaces target
 * - Props and styles are both deep merged
 */
/**
 * Since style or props overrides can be an object *or* a function, we need to handle
 * the case that one of them is a function. We do this by returning a new
 * function that deep merges the result of each style override
 */
export declare function useOverrides(defaults: {
    [x: string]: React.ComponentType<any>;
}, overrides?: Overrides): {
    [x: string]: [React.ComponentType<any>, {}];
};