import { ConditionDescription, ValueType } from '../../../operands';
export interface ElseCase<T> {
    type: 'else';
}
export interface EmptyCaseBuilder<T> {
    when(condition: ConditionDescription, then: T): CaseBuilder<T>;
}
export interface CaseBuilder<T> {
    when(condition: ConditionDescription, then: T): CaseBuilder<T>;
    else(value: T): ElseCase<T>;
}
export declare function caseWhen<T extends ValueType>(fn: (builder: EmptyCaseBuilder<T>) => CaseBuilder<T> | ElseCase<T>): T;