tuple.md

Tuple

The tuples feature provides concise syntax to group multiple data elements in a lightweight data structure. The following example shows how a type can ask to inject a tuple argument into it:

using Shouldly;
using Pure.DI;

DI.Setup(nameof(Composition))
    .Bind<IEngine>().To<ElectricEngine>()
    .Bind<Coordinates>().To(() => new Coordinates(10, 20))
    .Bind<IVehicle>().To<Car>()

    // Composition root
    .Root<IVehicle>("Vehicle");

var composition = new Composition();
var vehicle = composition.Vehicle;

interface IEngine;

class ElectricEngine : IEngine;

readonly record struct Coordinates(int X, int Y);

interface IVehicle
{
    IEngine Engine { get; }
}

class Car((Coordinates StartPosition, IEngine Engine) specs) : IVehicle
{
    // The tuple 'specs' groups the initialization data (like coordinates)
    // and dependencies (like engine) into a single lightweight argument.
    public IEngine Engine { get; } = specs.Engine;
}

Running this code sample locally

• Make sure you have the .NET SDK 10.0 or later installed

dotnet --list-sdk

• Create a net10.0 (or later) console application

dotnet new console -n Sample

• Add references to the NuGet packages
  • Pure.DI
  • Shouldly

dotnet add package Pure.DI
dotnet add package Shouldly

• Copy the example code into the Program.cs file

You are ready to run the example 🚀

dotnet run

Note

Tuples are useful for returning multiple values from a method or grouping related dependencies without creating explicit types.

The following partial class will be generated:

partial class Composition
{
  public IVehicle Vehicle
  {
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    get
    {
      Coordinates transientCoordinates459 = new Coordinates(10, 20);
      return new Car((transientCoordinates459, new ElectricEngine()));
    }
  }
}

Class diagram:

---
 config:
  maxTextSize: 2147483647
  maxEdges: 2147483647
  class:
   hideEmptyMembersBox: true
---
classDiagram
	ElectricEngine --|> IEngine
	Car --|> IVehicle
	Composition ..> Car : IVehicle Vehicle
	Car *--  ValueTupleᐸCoordinatesˏIEngineᐳ : ValueTupleᐸCoordinatesˏIEngineᐳ
	ValueTupleᐸCoordinatesˏIEngineᐳ *--  ElectricEngine : IEngine
	ValueTupleᐸCoordinatesˏIEngineᐳ *--  Coordinates : Coordinates
	namespace Pure.DI.UsageTests.BCL.TupleScenario {
		class Car {
				<<class>>
			+Car(ValueTupleᐸCoordinatesˏIEngineᐳ specs)
		}
		class Composition {
		<<partial>>
		+IVehicle Vehicle
		}
		class Coordinates {
				<<struct>>
		}
		class ElectricEngine {
				<<class>>
			+ElectricEngine()
		}
		class IEngine {
			<<interface>>
		}
		class IVehicle {
			<<interface>>
		}
	}
	namespace System {
		class ValueTupleᐸCoordinatesˏIEngineᐳ {
				<<struct>>
			+ValueTuple(Coordinates item1, IEngine item2)
		}
	}

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