import type { FieldReference } from '../query-items/field-references';
import type { ExprValue } from '../types/expr-value';
import type { ExpressionDef } from '../types/expression-def';
import { ExprAggregateFunction } from './expr-aggregate-function';
export declare abstract class ExprAsymmetric extends ExprAggregateFunction {
    readonly func: 'sum' | 'avg';
    readonly expr: ExpressionDef | undefined;
    readonly source?: FieldReference | undefined;
    constructor(func: 'sum' | 'avg', expr: ExpressionDef | undefined, source?: FieldReference | undefined, explicitSource?: boolean);
    isSymmetricFunction(): boolean;
    returns(ev: ExprValue): ExprValue;
    defaultFieldName(): undefined | string;
}