Difference between revisions of "cpp/execution/read env"
From cppreference.com
m (std:: in the signature.. But also I wonder how the signatures in exec.syn are supposed to work) |
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Revision as of 13:16, 4 October 2024
| Defined in header <execution>
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| std::execution::sender auto read_env( auto q ); |
(since C++26) | |
Parameters
| q | - | query object for querying the receiver's environment |
| This section is incomplete Reason: come up with template for CPO wording here |
For any query object q, the expression read_env(q) is expression-equivalent to /*make-sender*/(read_env, q).
Return value
Returns a sender that reaches into a receiver’s environment and pulls out the current value associated with the query object denoted by q.
Example
An example usage of this factory is to schedule dependent work on the receiver's scheduler, which can be obtained with read_env(get_scheduler):
std::execution::sender auto task = std::execution::read_env(std::execution::get_scheduler) | std::execution::let_value([](auto sched) { return std::execution::starts_on(sched, /*some nested work here*/); }); std::this_thread::sync_wait( std::move(task) ); // wait for it to finish
