import { CreateComputedOptions, type Signal } from '@angular/core';
/**
 * Creates a computed signal that tracks the previous value produced by the given computation.
 *
 * The first time the computed signal is evaluated, the returned signal emits the same value
 * as the current computation result. On subsequent evaluations, it emits the value from the prior update.
 *
 * @example
 * ```ts
 * const value = signal(0);
 * const previous = computedPrevious(value);
 *
 * effect(() => {
 *   console.log('Current value:', value());
 *   console.log('Previous value:', previous());
 * });
 *
 * // Logs initially:
 * // Current value: 0
 * // Previous value: 0
 *
 * value.set(1);
 *
 * // Logs:
 * // Current value: 1
 * // Previous value: 0
 *
 * value.set(2);
 *
 * // Logs:
 * // Current value: 2
 * // Previous value: 1
 * ```
 *
 * @param computation A function that returns the current value. Typically, this is a signal accessor.
 * @param options Optional computed signal configuration.
 * @returns A signal that emits the previous value returned by the computation.
 */
export declare function computedPrevious<T>(computation: () => T, options?: CreateComputedOptions<T>): Signal<T>;