[kixelated]

Problem

rust2-ts refused parts of the stable std::future and std::task API (found by #519): future::ready and everything on its Ready, Debug of a Poll, Pending, and PollFn, Poll::from, hashing a Poll, a Pending's clone, and Waker::clone_from. No moq consumer calls these; the maintainer plans all of std regardless.

Survey of the stable API: these already translated and stay as they are: pending, poll_fn, IntoFuture (std's and a crate's own), Poll's map, map_ok, map_err, is_ready, is_pending, ==, ordering, Clone, ?, ready!, Context::from_waker and waker, and Waker's wake, wake_by_ref, will_wake, data, vtable, noop, clone, and From<Arc<W>>.

Approach

• future::ready(v) is a new rt.Ready<T>: an rt.Future whose first poll or into_inner takes v and a later one panics with std's message. A value nothing took drops with it, by the dropper ready is given. It has $move, clone, and Debug (Ready(Some(..)), or Ready(None) once taken), and is a dyn Future as itself.
• Debug of a Poll is rt.fmtPoll, with rt.OuterPending passed where the Poll holds one that can be pending. Pending and PollFn write their name, as std's do.
• Hashing a Poll is rt.hashPoll: its variant as an isize, then what it holds, as std's derived Hash writes them.
• Poll::from(v) is v, as Some(v) already is. Every Pending, whether cloned or made as a zero-sized constant, is rt.NEVER.
• Waker::clone_from is rt.wakerCloneFrom, one of the runtime's CloneFroms, which clones and drops only where the waker it has would not will_wake the source, as std's does, so a waker in an Option or an array clones over another by it too.
• Debug of a Waker, Context, or RawWakerVTable writes addresses, so it is now refused with that reason instead of "unsupported call".

Tests: a new lang/futures differential fixture. It covers a Ready polled, awaited, into_innered, cloned before and after its poll, behind a dyn Future, and of (), Option<Option<_>>, and text. Its value's drop order is checked unpolled, dropped, polled, taken, and moved into an async block. Polling it twice panics with `Ready` polled after completion, and into_inner after a poll with std's other message. A Pending never completes over many polls, boxed or cloned. Debug is checked plain, with #, and with width, hex, and zero-pad specs, for nested Poll<Poll<u8>> too. It also hashes Polls, uses them as set keys, and calls clone_from on a waker in a variable and in a field, checking Arc counts and wakes. The reject fixture gains a Ready of a Poll and Debug of a Waker.

Impact

• Public API: the translator's output. New runtime exports: rt.Ready, rt.fmtPoll, rt.hashPoll, rt.wakerCloneFrom, rt.wakerCloneFromFn. No breaking change.

Alternatives

• Treating Waker::clone_from as *self = source.clone(): the Arc counts end the same, but a waker an executor gives would see a clone and a drop std never makes.
• Debug of a Waker with made-up addresses: it could never match native output, so it stays refused.

Follow-ups

• Wakers made from a RawWaker (new quest): RawWakerVTable::new, RawWaker::new, Waker::from_raw, Waker::new, RawWaker::from(Arc), and == of vtables.
• Out of std::future/std::task, seen in the survey: AssertUnwindSafe (also a Future) is refused, since it can't be constructed, and String::from_utf8_lossy is an unsupported call. Both are reported for planning.

Review

Codex (quest review, gpt-6.1-sol, medium), round 2 on head 89f62ff reported no findings. That head merges origin/main through #538 after the queue dropped the PR for a conflict: main moved clone_from onto the runtime's CloneFrom functions, so Waker::clone_from is now rt.wakerCloneFrom, an entry of std_clone_from, instead of a special case in mir/call.rs, which also covers a waker in an Option or an array (fixture extended). just ci passes on it. Head cc875dc adds only a conflict-free merge of origin/main (#529); the lang::futures and reject fixtures pass on it, and the full suite is left to the merge queue.

• Round 1 (head 804a75a): no findings.

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Commits

Reviewing files that changed from the base of the PR and between 8b51ae9 and cc875dc.

Files ignored due to path filters: 1

• ts/Cargo.lock is excluded by !**/*.lock

Files selected for processing: 30

• quest/m3/README.md
• quest/m3/ts-raw-waker.md
• ts/README.md
• ts/fixtures/lang/futures/Cargo.toml
• ts/fixtures/lang/futures/expected/core/option.ts
• ts/fixtures/lang/futures/expected/core/task/poll.ts
• ts/fixtures/lang/futures/expected/futures.Count.ts
• ts/fixtures/lang/futures/expected/futures.Held.ts
• ts/fixtures/lang/futures/expected/futures.Later.ts
• ts/fixtures/lang/futures/expected/futures.Logged.ts
• ts/fixtures/lang/futures/expected/futures.ts
• ts/fixtures/lang/futures/expected/harness.ts
• ts/fixtures/lang/futures/expected/lib.ts
• ts/fixtures/lang/futures/src/futures.rs
• ts/fixtures/lang/futures/src/lib.rs
• ts/fixtures/lang/futures/ts.toml
• ts/fixtures/reject/census.txt
• ts/fixtures/reject/expected.txt
• ts/fixtures/reject/src/futures.rs
• ts/fixtures/reject/ts.toml
• ts/runtime/rt/task.ts
• ts/src/lower/collections.rs
• ts/src/lower/consts.rs
• ts/src/lower/drop.rs
• ts/src/lower/fmt.rs
• ts/src/lower/library.rs
• ts/src/lower/mir/rvalue.rs
• ts/src/lower/mod.rs
• ts/src/lower/task.rs
• ts/tests/fixtures.rs

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[moq-bot]

quest land watch: the merge queue removed this pull request at f2d25fb because it conflicts with main (merge_conflict).

The land fixer works on it in the background, and the watcher re-enqueues it at the back of the queue once it is fixed or judged flaky, or hands it back here with what it needs.

(written by quest land watch)

[moq-bot]

quest land watch: armed auto-merge on this pull request at ad17485, so it joins the back of the merge queue once its required checks pass, with the land fixer's fix (codex / Codex): Merged base and re·solved clone_from conflict preserving Waker and container/slice paths; passed in ts/ with pinned nightly: cargo build --locked -p rust2-ts; cargo test --locked -p rust2-ts; cargo test --locked -p lang-futures-fixture -p reject-fixture; cargo clippy --locked -p rust2-ts --all-targets -- -D warnings; cargo fmt --all --check; tsc -p runtime..

(written by quest land watch)