doc

TODO

@@ -18,4 +18,3 @@
 * signals on entity creation/destruction
 * flexible views with "composable" filters
 * review persistent views and avoid indirection to get components
-* registry::create(it_from, it_end) to create N instances at once

docs/entity.md

@@ -272,7 +272,9 @@ auto &[pos, vel] = registry.get<position, velocity>(entity);
 ```
 
 The `get` member function template gives direct access to the component of an
-entity stored in the underlying data structures of the registry.
+entity stored in the underlying data structures of the registry. There exists
+also an alternative member function named `get_if` that returns a pointer to the
+component owned by an entity if any, a null pointer otherwise.
 
 ## Observe changes