Issue 4438: Bad expression in [exec.when.all]

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4438. Bad expression in [exec.when.all]

Section: 33.9.12.12 [exec.when.all] Status: New Submitter: Eric Niebler Opened: 2025-10-30 Last modified: 2025-10-31

Priority: Not Prioritized

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Discussion:

33.9.12.12 [exec.when.all] p5 reads as follows:

-5- Let make-when-all-env be the following exposition-only function template:
template<class Env>
  constexpr auto make-when-all-env(inplace_stop_source& stop_src,        // exposition only
                                   Env&& env) noexcept {
  return see below;
}
Returns an object e such that

(5.1) — decltype(e) models queryable, and

(5.2) — e.query(get_stop_token) is expression-equivalent to state.stop-src.get_token(), and

(5.3) — given a query object q with type other than cv stop_token_t and whose type satisfies forwarding-query, e.query(q) is expression-equivalent to get_env(rcvr).query(q).

The problem is with "state.stop-src.get_token()" in bullet (5.2). There is no state object here. This expression should be stop_src.get_token().

Proposed resolution:

This wording is relative to N5014.

Modify 33.9.12.12 [exec.when.all] as indicated:
-5- Let make-when-all-env be the following exposition-only function template:
```
template<class Env>
  constexpr auto make-when-all-env(inplace_stop_source& stop_src,        // exposition only
                                   Env&& env) noexcept {
  return see below;
}
```
Returns an object e such that
- (5.1) — decltype(e) models queryable, and
- (5.2) — e.query(get_stop_token) is expression-equivalent to state.stop-srcstop_src.get_token(), and
- (5.3) — given a query object q with type other than cv stop_token_t and whose type satisfies forwarding-query, e.query(q) is expression-equivalent to get_env(rcvr).query(q).