Point.cs

using System;

namespace ReadOnlyStructs
{
    public readonly struct Point
    {
        public Point(double x, double y)
        {
            X = x;
            Y = y;
        }

        public double X { get; }
        public double Y { get; }
        public double DistanceFromOrigin()
        {
            return Math.Sqrt(X * X + Y * Y);
        }
    }
}