Extension methods

Forms that compile (4)

Syntax	Description	Note
ExtStaticHelpers.Twice(2)	Calling by type name
public static int Twice(this int n)	Adding to a built-in type
public static int Double(this ExtPoint p)	Adding to your own value type
public static float Flat(this Vector3 v)	Adding to a runtime type	It can be written without holding the type’s definition.

Declaration and calling

Calling by type name

using UnityEngine;
using Tsukimi;

public static class ExtStaticHelpers
{
    public static int Twice(int n) { return n * 2; }
}

public class ExtStatic : TsukimiBehaviour
{
    void Start()
    {
        Debug.Log(ExtStaticHelpers.Twice(2));   // => 4
    }
}

Adding to a built-in type

using UnityEngine;
using Tsukimi;

public static class ExtIntHelpers
{
    public static int Twice(this int n) { return n * 2; }
}

public class ExtPrimitive : TsukimiBehaviour
{
    void Start()
    {
        Debug.Log(2.Twice());   // => 4
    }
}

Adding to your own value type

It can be added to a struct you declared yourself too.

using UnityEngine;
using Tsukimi;

public struct ExtPoint
{
    public int X;
}

public static class ExtPointHelpers
{
    public static int Double(this ExtPoint p) { return p.X * 2; }
}

public class ExtStruct : TsukimiBehaviour
{
    void Start()
    {
        ExtPoint p = new ExtPoint();
        p.X = 2;
        Debug.Log(p.Double());   // => 4
    }
}

Adding to a runtime type

It can be added to types the runtime exposes too.

using UnityEngine;
using Tsukimi;

public static class ExtVectorHelpers
{
    public static float Flat(this Vector3 v) { return v.x + v.z; }
}

public class ExtEnvironment : TsukimiBehaviour
{
    void Start()
    {
        Debug.Log(Vector3.one.Flat());   // => 2
    }
}