Implement AsComponents for tuples.

Cargo.toml

@@ -168,6 +168,7 @@ num-traits = "0.2"
 once_cell = "1.17"
 ordered-float = "4.2"
 parking_lot = "0.12"
+paste = "1.0.12"
 pathdiff = "0.2"
 pico-args = "0.5"
 ply-rs = { version = "0.1", default-features = false }

crates/re_types_core/Cargo.toml

@@ -41,6 +41,7 @@ arrow2 = { workspace = true, features = [
 backtrace.workspace = true
 document-features.workspace = true
 once_cell.workspace = true
+paste.workspace = true
 smallvec.workspace = true
 thiserror.workspace = true
 

crates/re_types_core/src/lib.rs

@@ -93,6 +93,7 @@ mod loggable_batch;
 mod result;
 mod size_bytes;
 mod tuid;
+mod tuple;
 
 pub use self::archetype::{
     Archetype, ArchetypeName, GenericIndicatorComponent, NamedIndicatorComponent,

crates/re_types_core/src/tuple.rs

@@ -0,0 +1,47 @@
+//! Implements [`AsComponents`] for tuples.
+
+use crate::{AsComponents, MaybeOwnedComponentBatch};
+
+macro_rules! impl_as_components_for_tuples {
+    // This recursive macro trick is from <https://stackoverflow.com/questions/55553281/>.
+    ( $_dropped:literal, $( $name:literal, )* ) => {
+        paste::paste! {
+            /// A tuple of bundles may act as a bundle.
+            impl<$( [<B $name>] : AsComponents ),*>
+                AsComponents for ($( [<B $name>], )*)
+            {
+                fn as_component_batches(
+                    &self,
+                ) -> Vec<MaybeOwnedComponentBatch<'_>> {
+                    #[allow(unused_mut)]
+                    let mut vector = Vec::new();
+                    $(
+                        vector.extend(self.$name.as_component_batches());
+                    )*
+                    vector
+                }
+
+                fn num_instances(&self) -> usize {
+                    0 $( .max(self.$name.num_instances()) )*
+                }
+
+                fn to_arrow(
+                    &self
+                ) -> crate::SerializationResult<
+                    Vec<(::arrow2::datatypes::Field, Box<dyn ::arrow2::array::Array>)>,
+                > {
+                    #[allow(unused_mut)]
+                    let mut vector = Vec::new();
+                    $(
+                        vector.extend(self.$name.to_arrow()?);
+                    )*
+                    Ok(vector)
+                }
+            }
+        }
+        impl_as_components_for_tuples!($( $name, )*);
+    };
+    () => {};
+}
+
+impl_as_components_for_tuples!(9999, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,);