Return an iterator pointing to the key-value pair associated with the
specified key in a given
object, if there is one.
iterator find(KeyType const& key);
An iterator pointing to the key-value pair associated with
*this at the point of the call, or
if there is no entry for the specified
Any exception thrown by the application of the
may be called concurrently with any other member function of
jss::concurrent_map on a given instance
(except for the constructor and destructor) without external synchronization.