export declare class MathUtil {
    static RADIAN: number;
    static clamp(value: number, min: number, max: number): number;
    static clamp01(value: number): number;
    static isNumber(n: any): n is number;
    static sign(x: number): number;
    static angleToRadian(n: number): number;
    static lerp(s: number, e: number, p: number): number;
}