CovarianceContravariance

Covariance & Contravariance

📚 Konu

Generic variance: covariance (out), contravariance (in), invariance.

🔑 Kavramlar

• Covariance (out): T sadece return type - IProducer → IProducer
• Contravariance (in): T sadece parameter - IConsumer → IConsumer
• Invariance: T hem input hem output - no conversion

💻 Kullanım

cd samples/02-Intermediate/CovarianceContravariance
dotnet run

🎓 Örnekler

// Covariance
public interface IProducer<out T> {
    T Produce();
}
IProducer<Dog> → IProducer<Animal>  // ✅

// Contravariance
public interface IConsumer<in T> {
    void Consume(T item);
}
IConsumer<Animal> → IConsumer<Dog>  // ✅

💡 Rules

• out: T only in return positions
• in: T only in parameter positions
• Neither: Invariant