Policy class defining that hard undefined behaviour should occur on incorrect narrow and wide value, error or exception observation.

Inherits publicly from base, and simply defines its wide value, error and exception observer policies to call their corresponding narrow editions.

Included by <basic_result.hpp>, and so is always available when basic_result is available.

Requires: Nothing.

Namespace: BOOST_OUTCOME_V2_NAMESPACE::policy

Header: <boost/outcome/policy/all_narrow.hpp>