import { Observable } from 'rxjs';
import { SelectOption } from './select-option';
import { InjectionToken } from '@angular/core';
export declare const SELECT_OPTION_PROVIDER: InjectionToken<SelectOptionProvider<any>>;
export interface SelectOptionProvider<T = any> {
    type(): 'number' | 'object' | 'string' | 'date';
    provide(search: string | null): Observable<SelectOption<T>[]>;
    label(value: T): string;
    trackBy?(value: T | undefined): any;
}