import { Schema, RefinableSchema, TransformableSchema, DefaultableSchema, NullableSchema } from '../types';
/**
 * Literal schema interface
 */
export interface LiteralSchema<T extends string | number | boolean | null | undefined> extends Schema<T>, RefinableSchema<T, LiteralSchema<T>>, TransformableSchema<T, LiteralSchema<T>>, DefaultableSchema<T, LiteralSchema<T>>, NullableSchema<T, LiteralSchema<T>> {
    readonly _tag: 'LiteralSchema';
    readonly value: T;
}
/**
 * Creates a schema that validates that a value exactly matches the provided literal value
 *
 * @param value The literal value to match against
 * @returns A schema that validates against the exact literal value
 *
 * @example
 * const adminTypeSchema = literal('admin');
 * const userTypeSchema = literal('user');
 * const boolSchema = literal(true);
 * const nullSchema = literal(null);
 */
export declare function literal<T extends string | number | boolean | null | undefined>(value: T): LiteralSchema<T>;