类型'foo.Phyl.DSpeed'已经定义了一个名为'DSpeed'的成员，它具有相同的参数类型

Question

While making a simple C# physics simulator, I ran across some complications and fixed all of them. At the end another problem popped out;

"Type 'Ball_and_gravity.Phyl.DSpeed' already defines a member called 'DSpeed' with the same parameter types"

It's located at the constructors. I have no idea what to do.

    public struct DSpeed : ISpeed, IAngleSpeed
    {
        public double Angle { get; set; }
        public double Speed { get; set; }
        public double XSpeed { get; set; }
        public double YSpeed { get; set; }

        public DSpeed(double ang, double sp)
        {
            Angle = ang;
            Speed = sp;

            XSpeed = Math.Sin(Angle) * Speed;
            YSpeed = Math.Cos(Angle) * Speed;
        }

        public DSpeed(double xs, double ys)
        {
            XSpeed = xs;
            YSpeed = ys;

            DPoint p1 = new DPoint(0, 0);
            DPoint p2 = new DPoint(XSpeed, YSpeed);
            Speed = p1.GetDistance(p2);
            Angle = Math.Atan2(XSpeed, YSpeed);
        }
    }

What's the problem here?

Answer 1

In this case, both methods use 2 doubles. for the compiler is the same thing.

for more info

Member Overloading on .Net

Answer 2

Your proposed solution of using float parameters is not recommendable, as it makes the API of your struct very opaque to the client code. Even if you're the only user of your library, you can almost be sure to be pulling your hair out a few months from now over why your code is failing, when you accidentally call the wrong constructor. Not to mention the obvious reason for both of the types float and double existing, namely the difference in precision.

You should consider introducing two named static factory methods to make it explicit how you're creating the instances. (You can probably come up with better names than the ones I've chosen below)

public struct DSpeed 
{
    public double Angle { get; private set; }
    public double Speed { get; private set; }
    public double XSpeed { get; private set; }
    public double YSpeed { get; private set; }

    private DSpeed(double angle, double speed, double xspeed, double yspeed)
    {
        Angle = angle;
        Speed = speed;
        XSpeed = xspeed;
        YSpeed = yspeed;
    }

    public static DSpeed FromAngle(double angle, double speed) 
    {
        var xspeed = Math.Sin(angle) * speed;
        var yspeed = Math.Cos(angle) * speed;
        return new DSpeed(angle, speed, xspeed, yspeed);
    }

    public static DSpeed FromXY(double xspeed, double yspeed)
    {
        DPoint p1 = new DPoint(0, 0);
        DPoint p2 = new DPoint(xspeed, yspeed);
        var speed = p1.GetDistance(p2);
        var angle = Math.Atan2(xspeed, yspeed);

        return new DSpeed(angle, speed, xspeed, yspeed);
    }
}

Also, I've made your property setters private, because mutable structs are evil