import { BooleanQuery, Query } from './query';
import { Token } from './tokens';
import { Expression } from './expression';
export declare class CaseStatement<DataType> {
    private readonly tokens;
    constructor(tokens: Token[]);
    when<Q extends Query<any>>(expression: Expression<boolean, boolean, string> | BooleanQuery<Q>): {
        then<T>(result: T): CaseStatement<DataType | T>;
    };
    else<T>(result: T): CaseStatement<DataType | T>;
    end(): Expression<DataType, true, 'case'>;
}