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Class used to specify that an asynchronous operation should return a future.
template< typename Allocator = std::allocator<void>> class use_future_t
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Description |
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The allocator type. The allocator is used when constructing the std::promise object for a given asynchronous operation. |
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Description |
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Obtain allocator. |
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Wrap a function object in a packaged task. |
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Specify an alternate allocator. |
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Construct using default-constructed allocator. Construct using specified allocator. |
The use_future_t
class is used to indicate that an asynchronous operation should return a
std::future object. A use_future_t object may be passed
as a handler to an asynchronous operation, typically using the special value
std::experimental::net::v1::use_future.
For example:
std::future<std::size_t> my_future = my_socket.async_read_some(my_buffer, std::experimental::net::use_future);
The initiating function (async_read_some in the above example) returns a future that will receive the result of the operation. If the operation completes with an error_code indicating failure, it is converted into a system_error and passed back to the caller via the future.