The Rust-side implementation of Linux's idr_for_each_entry macro. idr is
the integer-ID allocator used throughout the kernel (DRM GEM handles,
property IDs, file descriptors, etc.). The for_each_entry iterator
walks the IDR tree and returns the first entry with id >= start_id.
Previously the kernel API was stubbed at the C level. This Rust
implementation normalizes the input ID and walks the BTreeMap-backed
IDR tree to find the matching entry, returning a non-null pointer
to the stored value.
Cross-referenced with Linux lib/idr.c: idr_for_each_entry().
vasilito
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