import type { IrType } from "../types.js";
type AssignabilityCollector = {
    collectNarrowingCandidates(type: IrType): readonly IrType[];
    isAssignableTo(source: IrType, target: IrType): boolean;
};
export declare const narrowTypeByAssignableTarget: (collector: AssignabilityCollector, currentType: IrType | undefined, targetType: IrType, wantAssignable: boolean) => IrType | undefined;
export {};
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