using System;

public class Program

{

    public static void Main()

    {

        try { RRS t1 = new RRS("A", "B", "C"); Console.WriteLine(t1);}

        catch { Console.WriteLine("t1 not constructed");}

        try { RRS t2 = new RRS(null, "B", "C"); Console.WriteLine(t2);}

        catch { Console.WriteLine("t2 not constructed");}

        try {

            RRS t3 = new RRS 

            {

                A = string.Empty,

                B = "     ",

                C = null

            };

            Console.WriteLine(t3);

        }

        catch { Console.WriteLine("t3 not constructed");}

    }

}

​

public readonly record struct RRS

    {

    private readonly string a;

    public string A {

        get => a;

        init {

            a = string.IsNullOrWhiteSpace(value)

            ? throw new ArgumentException(nameof(A))

            : value;

        }

    }

    private readonly string b;

    public string B {

        get => b;

        init {

            b = string.IsNullOrWhiteSpace(value)

            ? throw new ArgumentException(nameof(B))

            : value;

        }

    }

    private readonly string c;

    public string C {

        get => c;

        init {

            c = string.IsNullOrWhiteSpace(value)

            ? throw new ArgumentException(nameof(C))

            : value;

        }

    }

    public RRS(string a, string b, string c) {

        A = string.IsNullOrWhiteSpace(a)

            ? throw new ArgumentException(nameof(a))

            : a;

        B = string.IsNullOrWhiteSpace(b)

            ? throw new ArgumentException(nameof(b))

            : b;

        C = string.IsNullOrWhiteSpace(c)

            ? throw new ArgumentException(nameof(c))

            : c;

    }

}

​

​