1+++ 2title = "`all_narrow`" 3description = "Policy class defining that hard undefined behaviour should occur on incorrect narrow and wide value, error or exception observation. Inherits publicly from `base`." 4+++ 5 6Policy class defining that hard undefined behaviour should occur on incorrect narrow and wide value, error or exception observation. 7 8Inherits publicly from {{% api "base" %}}, and simply defines its wide value, error and exception observer policies to call their corresponding narrow editions. 9 10Included by `<basic_result.hpp>`, and so is always available when `basic_result` is available. 11 12*Requires*: Nothing. 13 14*Namespace*: `BOOST_OUTCOME_V2_NAMESPACE::policy` 15 16*Header*: `<boost/outcome/policy/all_narrow.hpp>` 17