**Advanced Patterns - Functional Programming**

// Maybe<T> for safe null handling
Maybe<User> user = GetUserFromCache(id);
var email = user
    .Select(u => u.Email)
    .Filter(email => email.Contains("@"))
    .ValueOrDefault("no-reply@example.com");

// 🆕 v1.10.0: Enhanced OneOf support
OneOf<ValidationError, NotFoundError, User> result = ValidateAndCreateUser(request);
return result.Match(
    case1: error => BadRequest(error),
    case2: user => Ok(user)
);

// 🆕 v1.10.0: OneOf with auto-detection
public OneOf<ValidationError, NotFoundError, User> GetUser(int id) { /* logic */ }
return GetUser(id).ToIResult(); // 🆕 Automatic HTTP mapping!

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