import { IRNode } from "../types.js";
import type { SwiftConverterContext } from "./SwiftConverter.js";
/**
 * Applies the `unsupportedUnions` policy for an untagged union that survived
 * merging and has no usable discriminator.
 */
export declare function handleUnsupportedUnion(c: SwiftConverterContext, ir: IRNode): string;
/**
 * Pre-emission guard pass that throws on JSON Schema features Swift codegen
 * does not support: `not` and `patternProperties`. These are NOT silenced by
 * `unsupportedUnions: 'fallback'`.
 */
export declare function guardUnsupportedKeywords(_c: SwiftConverterContext, root: IRNode): void;
/**
 * Returns the `AnyCodable` helper struct that wraps arbitrary JSON values for
 * the unsupported-union fallback under `serializer: 'codable'`. Emitted only
 * when at least one fallback path requested it via `c.needsAnyCodable`.
 */
export declare function anyCodableHelper(c: SwiftConverterContext): string;