using System;

using System.Runtime.CompilerServices;

​

Print(Math.Sqrt(9)); // 取平方根

void Print(double number, 

           [CallerArgumentExpression("number")] string expr = null) 

    => Console.WriteLine(expr + $" = {number}");

​

IsTrue(1 + 1 == 3);

​

void IsTrue(bool value,

[CallerArgumentExpression("value")] string expr = null)

{

    if (!value)

        throw new ArgumentException($"{expr} 不是真的!");

}

​