Method all_instances_of

crates/rustc_codegen_spirv/src/linker/specializer.rs:2250–2260

Return the subset of `instances` that have `generic_id`. This is efficiently implemented via `BTreeMap::range`, taking advantage of the derived `Ord` on `Instance`, which orders by `generic_id` first, resulting in `instances` being grouped by `generic_id`.

(
        &self,
        generic_id: Word,
    )

    /// of the derived `Ord` on `Instance`, which orders by `generic_id` first,
    /// resulting in `instances` being grouped by `generic_id`.
    fn all_instances_of(
        &self,
        generic_id: Word,
    ) -> std::collections::btree_map::Range<'_, Instance<SmallVec<[CopyOperand; 4]>>, Word> {
        let first_instance_of = |generic_id| Instance {
            generic_id,
            generic_args: SmallVec::new(),
        };
        self.instances
            .range(first_instance_of(generic_id)..first_instance_of(generic_id + 1))
    }

    /// Allocate a new ID for `instance`, or return a cached one if it exists.
    /// If a new ID is created, `instance` is added to `propagate_instances_queue`,