From 21c582507ae2dc9d264c80719e39ac47d3b0122b Mon Sep 17 00:00:00 2001
From: HampusM <hampus@hampusmat.com>
Date: Wed, 28 Feb 2024 22:30:38 +0100
Subject: refactor(ecs): use better system input type filtering solution

---
 ecs/src/system.rs | 83 ++++---------------------------------------------------
 1 file changed, 6 insertions(+), 77 deletions(-)

(limited to 'ecs/src/system.rs')

diff --git a/ecs/src/system.rs b/ecs/src/system.rs
index d90e0a2..cbf004f 100644
--- a/ecs/src/system.rs
+++ b/ecs/src/system.rs
@@ -1,13 +1,13 @@
-use std::any::{Any, TypeId};
+use std::any::Any;
 use std::convert::Infallible;
 use std::fmt::Debug;
-use std::mem::{transmute_copy, ManuallyDrop};
 use std::ptr::addr_of_mut;
 
 use seq_macro::seq;
 
 use crate::component::Component;
 use crate::system::util::check_params_are_compatible;
+use crate::tuple::{FilterElement as TupleFilterElement, With as TupleWith};
 use crate::ComponentStorage;
 
 pub mod stateful;
@@ -166,80 +166,9 @@ pub struct NoInitParamFlag {}
 /// A type which can be used as input to a [`System`].
 pub trait Input: 'static {}
 
-pub trait InputFilter
+impl<InputT: Input, Tup> TupleFilterElement<Tup> for InputT
+where
+    Tup: TupleWith<Self>,
 {
-    type Filtered: FilteredInputs;
+    type Tuple = Tup::With;
 }
-
-pub trait FilteredInputs
-{
-    type InOptions: OptionInputs;
-
-    fn into_in_options(self) -> Self::InOptions;
-}
-
-macro_rules! impl_filtered_inputs {
-    ($cnt: tt) => {
-        seq!(I in 0..$cnt {
-            impl<#(Input~I: Input,)*> FilteredInputs for (#(Input~I,)*) {
-                type InOptions = (#(Option<Input~I>,)*);
-
-                fn into_in_options(self) -> Self::InOptions {
-                    #![allow(clippy::unused_unit)]
-                    (#(Some(self.I),)*)
-                }
-            }
-        });
-    };
-}
-
-seq!(N in 0..4 {
-    impl_filtered_inputs!(N);
-});
-
-pub trait OptionInputs
-{
-    fn take<Input: 'static>(&mut self) -> TakeOptionInputResult<Input>;
-}
-
-macro_rules! impl_option_inputs {
-    ($cnt: tt) => {
-        seq!(I in 0..$cnt {
-            impl<#(Input~I: 'static,)*> OptionInputs for (#(Option<Input~I>,)*) {
-                fn take<Input: 'static>(&mut self) -> TakeOptionInputResult<Input> {
-                    #(
-                        if TypeId::of::<Input~I>() == TypeId::of::<Input>() {
-                            let input = match self.I.take() {
-                                Some(input) => ManuallyDrop::new(input),
-                                None => {
-                                    return TakeOptionInputResult::AlreadyTaken;
-                                }
-                            };
-
-                            return TakeOptionInputResult::Found(
-                                // SAFETY: It can be transmuted safely since it is the
-                                // same type and the type is 'static
-                                unsafe { transmute_copy(&input) }
-                            );
-                        }
-                    )*
-
-                    TakeOptionInputResult::NotFound
-                }
-            }
-        });
-    };
-}
-
-seq!(N in 0..4 {
-    impl_option_inputs!(N);
-});
-
-pub enum TakeOptionInputResult<Input>
-{
-    Found(Input),
-    NotFound,
-    AlreadyTaken,
-}
-
-include!(concat!(env!("OUT_DIR"), "/system_input_impls.rs"));
-- 
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