refactor(ecs): make component::Sequence return metadata as array

1 files changed, 13 insertions, 5 deletions

diff --git a/ecs/src/component.rs b/ecs/src/component.rs
index 1fde5b4..bf19c9e 100644
--- a/ecs/src/component.rs
+++ b/ecs/src/component.rs
@@ -12,6 +12,7 @@ use crate::lock::{ReadGuard, WriteGuard};
 use crate::system::{ComponentRef, ComponentRefMut, Input as SystemInput};
 use crate::type_name::TypeName;
 use crate::uid::Uid;
+use crate::util::Array;
 use crate::{EntityComponent, World};
 
 pub mod local;
@@ -170,9 +171,12 @@ pub trait Sequence
     where
         Self: 'component;
 
+    /// The number of components in this component sequence.
+    const COUNT: usize;
+
     fn into_vec(self) -> Vec<Box<dyn Component>>;
 
-    fn metadata() -> Vec<Metadata>;
+    fn metadata() -> impl Array<Metadata>;
 
     fn added_event_ids() -> Vec<Uid>;
 
@@ -271,14 +275,16 @@ macro_rules! inner {
                 type Refs<'component> = (#(Comp~I::Ref<'component>,)*)
                     where Self: 'component;
 
+                const COUNT: usize = $c + 1;
+
                 fn into_vec(self) -> Vec<Box<dyn Component>>
                 {
                     Vec::from_iter([#(Box::new(self.I) as Box<dyn Component>,)*])
                 }
 
-                fn metadata() -> Vec<Metadata>
+                fn metadata() -> impl Array<Metadata>
                 {
-                    vec![
+                    [
                         #(
                             Metadata {
                                 id: Comp~I::id(),
@@ -357,14 +363,16 @@ impl Sequence for ()
     type MutRefs<'component> = ();
     type Refs<'component> = ();
 
+    const COUNT: usize = 0;
+
     fn into_vec(self) -> Vec<Box<dyn Component>>
     {
         Vec::new()
     }
 
-    fn metadata() -> Vec<Metadata>
+    fn metadata() -> impl Array<Metadata>
     {
-        Vec::new()
+        []
     }
 
     fn added_event_ids() -> Vec<Uid>