import { OmitProperty } from "./omit-property.js";
/**
 * Provides convenience functions for object mappers.
 *
 * Use these to map to constant values, or to omit the property.
 *
 * @category runtime
 */
export declare const mapFrom: {
    /**
     * Returns a function that always returns a constant value.
     *
     * ```ts
     * const objectMapperSchema = {
     *   out: mapFrom.constant('Hello'),
     * }
     * ```
     */
    constant<TValue>(this: void, value: TValue): () => TValue;
    /**
     * Returns the symbol {@linkcode OmitProperty}, which will tell the
     * mapper to omit the property from the output object.
     *
     * ```ts
     * const objectMapperSchema = {
     *   out: mapFrom.omit,
     * }
     * ```
     */
    omit(this: void): OmitProperty;
    /**
     * Always map the output value to `null`
     *
     * ```ts
     * const objectMapperSchema = {
     *   out: mapFrom.null,
     * }
     * ```
     */
    null(this: void): null;
    /**
     * Maps the specified properties to themselves as is
     *
     * ```ts
     * const objectMapperSchema = {
     *   ...mapFrom.pick('a', 'b', 'c', 'd'),
     * }
     * ```
     */
    pick<TKey extends PropertyKey>(this: void, key: TKey, ...keys: TKey[]): { [K in TKey]: K; };
    /**
     * Always map the output value to `undefined`
     *
     * ```ts
     * const objectMapperSchema = {
     *   out: mapFrom.undefined,
     * }
     * ```
     */
    undefined(this: void): undefined;
};
//# sourceMappingURL=map-from.d.ts.map