Nested Queries

crates/bevy_ecs/macros/src/query_data.rs

@@ -301,6 +301,17 @@ pub fn derive_query_data_impl(input: TokenStream) -> TokenStream {
                     }
                 }
 
+                // SAFETY: Access is read-only
+                unsafe impl #user_impl_generics #path::query::IterQueryData
+                for #read_only_struct_name #user_ty_generics #user_where_clauses {}
+
+                // SAFETY: All fields only access the current entity
+                unsafe impl #user_impl_generics #path::query::SingleEntityQueryData
+                for #read_only_struct_name #user_ty_generics #user_where_clauses
+                // Make these HRTBs with an unused lifetime parameter to allow trivial constraints
+                // See https://github.com/rust-lang/rust/issues/48214
+                where #(for<'__a> #field_types: #path::query::QueryData<ReadOnly: #path::query::SingleEntityQueryData>,)* {}
+
                 impl #user_impl_generics #path::query::ReleaseStateQueryData
                 for #read_only_struct_name #user_ty_generics #user_where_clauses
                 // Make these HRTBs with an unused lifetime parameter to allow trivial constraints
@@ -359,6 +370,20 @@ pub fn derive_query_data_impl(input: TokenStream) -> TokenStream {
                 }
             }
 
+            // SAFETY: All fields are iterable
+            unsafe impl #user_impl_generics #path::query::IterQueryData
+            for #struct_name #user_ty_generics #user_where_clauses
+            // Make these HRTBs with an unused lifetime parameter to allow trivial constraints
+            // See https://github.com/rust-lang/rust/issues/48214
+            where #(for<'__a> #field_types: #path::query::IterQueryData,)* {}
+
+            // SAFETY: All fields only access the current entity
+            unsafe impl #user_impl_generics #path::query::SingleEntityQueryData
+            for #struct_name #user_ty_generics #user_where_clauses
+            // Make these HRTBs with an unused lifetime parameter to allow trivial constraints
+            // See https://github.com/rust-lang/rust/issues/48214
+            where #(for<'__a> #field_types: #path::query::SingleEntityQueryData,)* {}
+
             impl #user_impl_generics #path::query::ReleaseStateQueryData
             for #struct_name #user_ty_generics #user_where_clauses
             // Make these HRTBs with an unused lifetime parameter to allow trivial constraints

crates/bevy_ecs/macros/src/world_query.rs

@@ -156,6 +156,15 @@ pub(crate) fn world_query_impl(
                 #( <#field_types>::update_component_access(&state.#named_field_idents, _access); )*
             }
 
+            fn init_nested_access(
+                state: &Self::State,
+                _system_name: Option<&str>,
+                _component_access_set: &mut #path::query::FilteredAccessSet,
+                _world: #path::world::unsafe_world_cell::UnsafeWorldCell,
+            ) {
+                #( <#field_types>::init_nested_access(&state.#named_field_idents, _system_name, _component_access_set, _world); )*
+            }
+
             fn init_state(world: &mut #path::world::World) -> #state_struct_name #user_ty_generics {
                 #state_struct_name {
                     #(#named_field_idents: <#field_types>::init_state(world),)*
@@ -171,6 +180,10 @@ pub(crate) fn world_query_impl(
             fn matches_component_set(state: &Self::State, _set_contains_id: &impl Fn(#path::component::ComponentId) -> bool) -> bool {
                 true #(&& <#field_types>::matches_component_set(&state.#named_field_idents, _set_contains_id))*
             }
+
+            fn update_archetypes(_state: &mut Self::State, _world: #path::world::unsafe_world_cell::UnsafeWorldCell) {
+                #(<#field_types>::update_archetypes(&mut _state.#named_field_idents, _world);)*
+            }
         }
     }
 }

crates/bevy_ecs/src/query/access.rs

@@ -1,5 +1,5 @@
 use crate::component::ComponentId;
-use crate::world::World;
+use crate::world::unsafe_world_cell::UnsafeWorldCell;
 use alloc::{format, string::String, vec, vec::Vec};
 use core::{fmt, fmt::Debug};
 use derive_more::From;
@@ -991,7 +991,7 @@ impl AccessConflicts {
         }
     }
 
-    pub(crate) fn format_conflict_list(&self, world: &World) -> String {
+    pub(crate) fn format_conflict_list(&self, world: UnsafeWorldCell) -> String {
         match self {
             AccessConflicts::All => String::new(),
             AccessConflicts::Individual(indices) => indices
@@ -1000,7 +1000,7 @@ impl AccessConflicts {
                     format!(
                         "{}",
                         world
-                            .components
+                            .components()
                             .get_name(ComponentId::new(index))
                             .unwrap()
                             .shortname()