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Section: 33.10.8 [futures.shared.future] Status: Resolved Submitter: Alisdair Meredith Opened: 2010-01-23 Last modified: 2021-06-06
Priority: Not Prioritized
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Discussion:
The revised futures package in the current working paper simplified the is_ready/has_exception/has_value set of APIs, replacing them with a single 'valid' method. This method is used in many places to signal pre- and post- conditions, but that edit is not complete. Each method on a shared_future that requires an associated state should have a pre-condition that valid() == true.
[ 2010-01-28 Moved to Tentatively Ready after 5 positive votes on c++std-lib. ]
[ 2010 Pittsburgh: ]
Moved to
NAD EditorialResolved. Rationale added below.
Rationale:
Solved by N3058.
Proposed resolution:
Insert the following extra paragraphs:
In [futures.shared_future]
shared_future();4 Effects: constructs ...
Postcondition: valid() == false.
Throws: nothing.
void wait() const;Requires: valid() == true.
22 Effects: if the associated ...
template <class Rep, class Period> bool wait_for(const chrono::duration<Rep, Period>& rel_time) const;Requires: valid() == true.
23 Effects: if the associated ...
template <class Clock, class Duration> bool wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;Requires: valid() == true.
25 Effects: blocks until ...