Platform Notes | USearch for Rust

§ What This Binding Does Not Expose

These C entry points also take a deferred completion, but the crate calls them blocking, whatever receiver you hold:

The load_* family, view_nvme, metadata and metadata_buffer, with each load config’s executor choosing where it fans out.
clear, which runs on the calling thread under &mut DenseIndex.
Cursor and search-stream pulls, which run on the executor of the receiver that opened them, and open only from a blocking one.

init_ram, init_vram and view_ram block in C as well.

§ Design

A thin layer over the C ABI. Every name follows c/usearch/: a C verb usearch_dense_<verb> is a <verb> here, each module mirrors one header, a verb’s argument struct becomes its Dense*Config, and every wrapper’s documentation names the C symbol it calls. Enums mirror C enums, never strings.
The receiver chooses, the verb stays. &DenseIndex runs a verb on the calling thread, on(&executor) blocks on an executor, and deferred(&executor) submits it, all with the same arguments.
Deferred calls use the language’s own idioms. status polls through usearch_outcome_status, wait blocks through usearch_outcome_wait, and a Deferred is IntoFuture, so .await polls the status word, since the library has no wake-up.
No life of its own. The binding starts no threads and keeps no queues; releasing a Deferred rides Drop, which waits for the call first.
Arenas are lent and reused, never shared. Every output whose length scales with the call lands in an arena the caller passes; the result borrows it, so the borrow checker retires stale views at compile time.
Nothing costs anything until it is used. Blocking calls allocate no box, and an arena allocates only when a call writes into it.
Callers lend memory, never an allocator. No allocation callback crosses into the library: payload belongs to the index, placed by its constructor’s residency, and scratch belongs to the executor.
A deferred receiver refuses borrowed inputs at compile time. The Accepts bound admits only owned inputs, so a borrow the library would read after the verb returns never compiles.