Add Entity<T>.Valid/AliveOrNull/Throw

src/gaemstone.ECS/Entity.cs

@@ -39,9 +39,17 @@ public unsafe readonly partial struct Entity<TContext>
 	public static Entity<TContext> GetOrInvalid(World<TContext> world, Entity value)
 		=> new(world, value);
 	public static Entity<TContext>? GetOrNull(World<TContext> world, Entity value)
-		=> ecs_is_valid(world, value) ? new(world, value) : null;
+		=> new Entity<TContext>(world, value).ValidOrNull();
 	public static Entity<TContext> GetOrThrow(World<TContext> world, Entity value)
-		=> ecs_is_valid(world, value) ? new(world, value) : throw new InvalidOperationException($"The entity {value} is not valid");
+		=> new Entity<TContext>(world, value).ValidOrThrow();
+
+	public Entity<TContext>? ValidOrNull() => IsValid ? this : null;
+	public Entity<TContext> ValidOrThrow() => IsValid ? this
+		: throw new InvalidOperationException($"The entity {this} is not valid");
+
+	public Entity<TContext>? AliveOrNull() => IsAlive ? this : null;
+	public Entity<TContext> AliveOrThrow() => IsAlive ? this
+		: throw new InvalidOperationException($"The entity {this} is not alive");
 
 	public void Delete()
 		=> ecs_delete(World, this);