Note: default is caf::actor; see fwd.hpp

TODO: use the equivalent C++20 constructor instead, once available.

Checks whether two floating point numbers are nearly equal.

Creates a new SSL connection on `fd`. The connection does not take ownership of the socket, i.e., does not close the socket when the SSL session end o

Creates a @ref flow::observable that reads and emits all values from this publisher.

Called when the `ucast_sub_state` receives new demand.

@pre `valid()`

Note: does not take ownership of the data.

Checks whether the current input is valid UTF-8. Stores the last position while scanning in order to avoid validating the same bytes again.

Returns the number of pending (delayed and scheduled) actions.

Gets a worker from the hub. @returns the next available worker (in LIFO order) or `nullptr` if the hub is currently empty.

Makes `item` available to the consumer. @returns the remaining demand.

Tries to enqueue a new element to the inbox. @threadsafe

Throws a `nesting_error` to indicate that `parent` is not allowing additional blocks of type `child`.

Asynchronously reads the entire file, character by character.

Asynchronously reads the entire file, line by line.