feat(engine-ecs): impl component::Sequence for component::Parts arrays

2 files changed, 17 insertions, 12 deletions

diff --git a/engine-ecs/src/actions.rs b/engine-ecs/src/actions.rs
index efef384..9e88011 100644
--- a/engine-ecs/src/actions.rs
+++ b/engine-ecs/src/actions.rs
@@ -69,7 +69,7 @@ impl Actions<'_>
     {
         debug_assert!(!entity_uid.is_pair());
 
-        if Comps::COUNT == 0 {
+        if components.cnt() == 0 {
             return;
         }
 
diff --git a/engine-ecs/src/component.rs b/engine-ecs/src/component.rs
index 681e546..157d79c 100644
--- a/engine-ecs/src/component.rs
+++ b/engine-ecs/src/component.rs
@@ -68,11 +68,10 @@ impl Debug for dyn Component
 /// A sequence of components.
 pub trait Sequence
 {
-    /// The number of components in this component sequence.
-    const COUNT: usize;
-
     type PartsArray: Array<Parts>;
 
+    fn cnt(&self) -> usize;
+
     fn into_parts_array(self) -> Self::PartsArray;
 }
 
@@ -242,12 +241,15 @@ pub struct AcquireLockError(#[source] LockError);
 
 macro_rules! inner {
     ($c: tt) => {
-        seq!(I in 0..=$c {
+        seq!(I in 0..$c {
             impl<#(IntoCompParts~I: IntoParts,)*> Sequence for (#(IntoCompParts~I,)*)
             {
-                const COUNT: usize = $c + 1;
+                type PartsArray = [Parts; $c];
 
-                type PartsArray = [Parts; $c + 1];
+                fn cnt(&self) -> usize
+                {
+                    $c
+                }
 
                 fn into_parts_array(self) -> Self::PartsArray
                 {
@@ -260,19 +262,22 @@ macro_rules! inner {
     };
 }
 
-seq!(C in 0..=16 {
+seq!(C in 0..17 {
     inner!(C);
 });
 
-impl Sequence for ()
+impl<const LEN: usize> Sequence for [Parts; LEN]
 {
-    type PartsArray = [Parts; 0];
+    type PartsArray = Self;
 
-    const COUNT: usize = 0;
+    fn cnt(&self) -> usize
+    {
+        self.len()
+    }
 
     fn into_parts_array(self) -> Self::PartsArray
     {
-        []
+        self
     }
 }